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Soil bacteria have an effective role in dissolving soil potassium. Bacillus mucilaginosus plays an effective role in dissolving potassium in the soil so that the plant may absorb it easily. The present study aimed to test the efficiency of bacteria in dissolving potassium present in the soil surrounding the roots of crops. B. mucilaginosus was isolated and diagnosed from the rhizosphere soil of Celery, Wheat, Basil and Alfalfa plants. The diagnosis included studying the isolates' culture, microscopic and biochemical characteristics. The laboratory study also included testing the efficiency of these bacterial isolates in dissolving potassium compounds in Modified Aleksandrov agar medium and estimating the dissolution coefficient. The results of isolation and identification of bacteria isolated from 19 out of 50 soil samples planted with different crops (Celery, Wheat, Basil and Alfalfa) showed that 8 isolates could dissolve potassium. The results of the microscopic examination of these eight isolates showed that they were sticky in shape, positive for Gram-staining, forming spores and the capsule, while the movement examination showed that they were positive for these tests (movement test). The biochemical tests and cultural characteristics showed that the eight isolates bear the characteristics of B. mucilaginosus. The results showed that the dissolution coefficient of potassium for the different isolates ranged between 2.28 and 1.14, while the type of sugar added to the culture medium increased the efficiency of bacterial isolates for potassium solubility. The study demonstrated the bacteria's efficiency in the rhizosphere region in dissolving potassium, which helps the plant use it easily.

L'ISWT o "Incremental Shuttle Walk Test" és una prova de caminada incremental que es realitza en un recorregut de 10 metres. La velocitat de la marxa augmenta cada minut i finalitza quan el pacient es troba massa fatigat per continuar o no pot mantenir la velocitat requerida. En una fulla de treball, el metge encarregat de supervisar la prova ha d'anotar certes mesures abans,durant i després de la prova. Durant la prova, el responsable ha d'estar atent a cada pas que fa el pacient entre els cons i, després de cada minut, ha de recollir dades sobre la freqüència cardíaca i la saturació d'oxigen en sang. L'objectiu d'aquest projecte és intentar digitalitzar la prova de l'ISWT, dissenyant una solució que faci més fàcil la feina al personal mèdic i com a mínim mantingui o incrementar l'eficàcia de la recopilació de dades. Des del Craax, fa temps que treballen en col·laboració amb l'Hospital Clínic de Barcelona, i ja tenen un sistema muntat i diversos dispositius útils per a altres proves. Alguns d'aquests dispositius els tenim a disposició i al llarg d'aquesta memòria podrem veure com els analitzem i busquem la manera d'utilitzar-los en la nostra solució. Podrem veure com anem integrant els diferents elements per millorar la pràctica de la prova, permetent al personal que durant la prova només s'hagi d'encarregar de supervisar la recopilació de dades, a més d'una navegació a través de l'aplicació senzilla i suficient per recopilar totes les dades necessàries i útils per a la prova. Aplicant els diversos coneixements adquirits al llarg de la carrera universitària i amb l'ajuda de l'equip directiu, s'ha desenvolupat una solució final que es considera satisfactòria d'acord amb els objectius i ofereix resultats positius en la seva consideració d'utilitat per a futures millores., ISWT de “Incremental Shuttle Walk Test” es una prueba de caminata incremental realizada a lo largo de un recorrido de 10 metros. La velocidad de marcha incrementa a cada minuto y este finaliza en el caso que el paciente se encuentre demasiado fatigado como para continuar o en caso de que no pueda mantener la velocidad requerida. En una hoja de trabajo el médico encargado de monitorizar la prueba, ha de anotar ciertas medidas anteriores, durante y posteriores de la prueba. Durante la prueba, el encargado ha de estar pendiente a cada paso por los conos que realiza el paciente, y tras cada minuto recoger datos de frecuencia cardiaca y saturación de oxígeno en sangre. El objetivo de este proyecto es intentar digitalizar la prueba del ISWT, diseñando así, una solución capaz de facilitar el trabajo al personal médico y como mínimo manteniendo o mejorando la eficacia de la recogida de datos. Desde el Craax llevan tiempo trabajando conjuntamente con el Hospital Clínic de Barcelona, ya tienen un sistema montado y diferentes dispositivos útiles para otras pruebas. Algunos de ellos los tenemos a disposición y a lo largo de esta memoria podremos observar como lo analizamos y buscamos poder utilizarlos en nuestra solución. Podremos ver como vamos encajando los diferentes elementos para mejorar la práctica de la prueba, permitiendo al personal que, durante la prueba únicamente tenga que encargarse de monitorizar la recogida de datos, además de una navegación a lo largo de la app sencilla y suficiente para recabar todos los datos necesarios y útiles para la prueba. Aplicando diferentes conocimientos adquiridos durante el recorrido universitario y con la ayuda del equipo dirigente, se ha desarrollado una solución final a considerar satisfactorio conforme los objetivos y de resultado positivo en su consideración de utilidad para futuras mejoras., The ISWT or "Incremental Shuttle Walk Test" is an incremental walking test performed over a 10-meter course. The walking speed increases every minute and ends when the client becomes too fatigued to continue or is unable to maintain the required speed. On a worksheet, the person in charge of monitoring the test must record certain pre-, during and post-test measurements. During the test, the responsible person must pay attention to each step taken by the client between the cones (shuttle) and, after each minute, collect data on heart rate and blood oxygen saturation. The objective of this project is to attempt to digitize the ISWT by designing a solution that makes the work easier for medical personnel and, at a minimum, maintains or improves the effectiveness of data collection. From Craax, they have been working collaboratively with the Hospital Clínic de Barcelona for some time, and they already have a system and various devices useful for other tests. Some of these devices are available to us, and throughout this report, we can see how we analyze them and seek ways to use them in our solution. We will see how we are integrating the different elements to improve the practice of the test, allowing the personnel during the test to only focus on monitoring data collection, along with simple and sufficient navigation through the app to gather all the necessary and useful data for the test Applying various acquired knowledge throughout the university journey and with the assistance of the leadership team, a final solution has been developed that is deemed satisfactory according to the objectives and yields positive results in its consideration of utility for future improvements.

Mohs micrographic surgery (MMS) is a surgical technique used to remove skin tumors with a complete evaluation of the margins. The keystone flap technique is generally used to repair large surgical defects on limbs. We present a case where a modified keystone flap technique was used to close a large defect after Mohs micrographic surgery in a patient with a basal cell carcinoma on the nose. An excellent functional and aesthetic result was obtained with no complications during or after the procedure. We offer a novel indication for this technique for surgical defects in this area.

Mohs micrographic surgery (MMS) is a surgical technique used to remove skin tumors with a complete evaluation of the margins. The keystone flap technique is generally used to repair large surgical defects on limbs. We present a case where a modified keystone flap technique was used to close a large defect after Mohs micrographic surgery in a patient with a basal cell carcinoma on the nose. An excellent functional and aesthetic result was obtained with no complications during or after the procedure. We offer a novel indication for this technique for surgical defects in this area.

Heat treatments are carried out on the wood to modify the hygroscopic properties and its dimensional stability. This allows low-grade wood to be used in exposed applications. This document provides a systematized bibliographic review related to the available technologies that allow heat treatment of wood. For this, scientific databases were consulted where previous studies with high temperature drying were found that served as the basis for the development of technologies that are used today. Patent databases were also consulted making the systematic use of the International Patent Classification (IPC) and Cooperative Patent Classification (CPC), the most promising codes were selected according to the histogram analysis. Finally, a marked trend was observed in recent years in the study and development of heat treatments applied to different timber species., Los tratamientos térmicos se realizan a la madera con el fin de modificar las propiedades higroscópicas y su estabilidad dimensional. Esto permite que madera de baja calidad pueda ser usada en aplicaciones de libre exposición. Este documento proporciona una revisión bibliográfica sistematizada relacionada con las tecnologías disponibles que permiten realizar tratamientos térmicos en madera. Para esto se consultaron bases de datos científicas en donde se encontraron estudios previos con secado a alta temperatura que sirvió de base para el desarrollo de las tecnologías que se usan en la actualidad. También se consultaron bases de datos de patentes haciendo el uso sistematizado de la Clasificación Internacional de Patentes (CIP) y la Clasificación cooperativa de Patentes (CCP), se seleccionaron los códigos más prometedores de acuerdo con el análisis del histograma. Por último, se observó una tendencia marcada para los últimos años en el estudio y desarrollo de los tratamientos térmicos aplicados a diferentes especies maderables.

Heat treatments are carried out on the wood to modify the hygroscopic properties and its dimensional stability. This allows low-grade wood to be used in exposed applications. This document provides a systematized bibliographic review related to the available technologies that allow heat treatment of wood. For this, scientific databases were consulted where previous studies with high temperature drying were found that served as the basis for the development of technologies that are used today. Patent databases were also consulted making the systematic use of the International Patent Classification (IPC) and Cooperative Patent Classification (CPC), the most promising codes were selected according to the histogram analysis. Finally, a marked trend was observed in recent years in the study and development of heat treatments applied to different timber species., Los tratamientos térmicos se realizan a la madera con el fin de modificar las propiedades higroscópicas y su estabilidad dimensional. Esto permite que madera de baja calidad pueda ser usada en aplicaciones de libre exposición. Este documento proporciona una revisión bibliográfica sistematizada relacionada con las tecnologías disponibles que permiten realizar tratamientos térmicos en madera. Para esto se consultaron bases de datos científicas en donde se encontraron estudios previos con secado a alta temperatura que sirvió de base para el desarrollo de las tecnologías que se usan en la actualidad. También se consultaron bases de datos de patentes haciendo el uso sistematizado de la Clasificación Internacional de Patentes (CIP) y la Clasificación cooperativa de Patentes (CCP), se seleccionaron los códigos más prometedores de acuerdo con el análisis del histograma. Por último, se observó una tendencia marcada para los últimos años en el estudio y desarrollo de los tratamientos térmicos aplicados a diferentes especies maderables.

Purpose This study aimed to make a comparative evaluation of the differences between the original façade (original) and the modified façade of the traditional Turkish Houses (collected from Afyonkarahisar city) based on perception. Design/Methodology/Approach In line with this purpose, digital images of eight sets of original and modified street silhouettes with gray color scales have been produced on the computer. Two different groups consisting of 80 people (architect and non-architect group) have evaluated the prepared images by the semantic differentiation scale consisting of the adjective pairs. The main hypothesis of the study is "The original façade would be more preferred than the modified façade". Also, gender, architect and non-architect group comparisons were made in the evaluations, too. Findings The results have shown that the participants liked the original traditional Turkish House façade more. The tidy/untidy and proportional/non-proportional adjective pairs have had the biggest difference in this evaluation. In another result, male participants have evaluated the traditional Turkish House façade views liked more for all dependent variables except for familiar / unfamiliar and qualified / unqualified adjective pairs compared to female participants. In addition, non-architects have liked more than architects the façade views of traditional Turkish Houses for adjective pairs that are beautiful / ugly, not impressive / unimpressive and interesting / uninteresting. On the other hand the architects have liked more than non-architects the façade view of traditional Turkish Houses for the proportional / non-proportional adjective pair. Research Limitations/Implications This study has been conducted only for Turkish Houses collected from Afyonkarahisar city. In addition, only architects and non-architects group attended for evaluation of the surveys. Social/Practical Implications According to the most important finding obtained from the study, the fact that, Bu çalışmada, geleneksel Türk Evlerinin orijinal cephesi (orijinal) ile değiştirilmiş cephesi (tadil edilmiş) arasındaki farkların algıya dayalı olarak karşılaştırmalı bir değerlendirmesi amaçlanmıştır. Bu amaç doğrultusunda bilgisayar ortamında gri tonlamayla renklendirilmiş sekiz takım orijinal ve modifiye edilmiş sokak silüetinin dijital görüntüleri üretilmiştir. Hazırlanan görseller, sıfat çiftlerinden oluşan anlamsal farklılaşma ölçeği ile 80 kişiden oluşan iki farklı grup tarafından değerlendirilmiştir. Araştırmada öncelikle "orijinal cephe modifiye cepheden daha çok tercih edilecektir" hipotezi üzerinde durulmuştur. Ayrıca değerlendirmelerde cinsiyet, mimar ve mimar olmayan grup karşılaştırmaları da yapılmıştır. Elde edilen sonuçlara göre katılımcılar orijinal geleneksel Türk Evi cephesini daha olumlu değerlendirmişlerdir. Bu değerlendirmedeki en büyük fark, düzenli / düzensiz ve orantılı / orantısız sıfat çiftinde olmuştur. Çalışmada cinsiyetin cephe algısı üzerindeki etkisi görülmekle birlikte, kadın katılımcıların daha olumsuz bir değerlendirme yaptığı sonucuna varılmıştır. Ayrıca mimar ve mimar olmayan katılımcıların değerlendirmeleri arasında dört sıfat çifti için önemli farklılıklar bulunmuştur. Bu çalışma ile literatürde ilk kez geleneksel Türk Evi cephelerinden oluşan sokak silüetlerinin değerlendirilmesi gerçekleştirilmiştir.

Widespread usage of pesticides in agricultural practice caused their residues to appear in water and food products intended for human consumption. The potential toxicity of these resources has raised awareness about pesticide tracking in the environment. Development of reliable electrochemical sensors for the on-site determination of pesticide concentrations is envisioned as an alternative to conventional chromatographic methods which are robust, expensive and require skilled work force. Modification of the working electrode surface can result in enhanced electrochemical response towards selected pesticide making such electrode convenient sensor for facile and efficient determination of pesticides in low concentrations. New generation of nanomaterials is applied in electrode modification in order to improve its sensitivity and selectivity. The present review summarizes significant advances in voltammetric detection of pesticides for the period of the past five years. The major focus of this review is set to the types of carbon and oxide based materials, metal nanoparticles, composites and other materials employed to upgrade standard electrode configurations such as glassy carbon and carbon paste electrodes, boron doped diamond electrodes, screen printed and film electrodes, metal and amalgam, and other kinds of electrodes.

Objective: To establish optimal cut-off values for the scores of the revised Fibromyalgia Impact Questionnaire (FIQR), the modified Fibromialgia Assessment Scale (FAS 2019mod), and the Polysymptomatic Distress Scale (PDS) in order to distinguish five levels of FM disease severity. Methods: Consecutive FM patients were evaluated with the three clinimetric indices, and each patient was required to answer the anchor question: 'In general, would you say your health is 1 = very good, 2 = good, 3 = fair, 4 = poor, or 5 = very poor?'-which represented the external criterion. Cut-off points were established through the interquartile reconciliation approach. Results: The study sample consisted of 2181 women (93.2%) and 158 men (6.8%), with a mean age of 51.9 (11.5) years, and mean disease duration was 7.3 (6.9) years. The overall median FIQR, FAS 2019 mod and PDS scores (25th-75th percentiles) were respectively 61.16 (41.16-77.00), 27.00 (19.00-32.00) and 19.0 (13.00-24.00). Reconciliation of the mean 75th and 25th percentiles of adjacent categories defined the severity states for FIQR: 0-23 for remission, 24-40 for mild disease, 41-63 for moderate disease, 64-82 for severe disease and >83 for very severe disease; FAS 2019 mod: 0-12 for remission, 13-20 for mild disease, 21-28 for moderate disease, 29-33 for severe disease and >33 for very severe disease; PDS: 0-5 for remission, 6-15 for mild disease, 16-20 for moderate disease, 21-25 for severe disease and >25 for very severe disease. Conclusions: Disease severity cut-offs can represent an important improvement in interpreting FM.

Urgency of the research. The problem of salinization of water is very common due to natural and anthropogenic factors, and industrial regions suffer the most. Thus, the priority direction is the development of low-waste technology of water purification from heavy metal ions.Target setting. Heavy metals are introduced into the aquatic systems significantly as a result of various industrial operations. The discharge of these pollutants into surface and groundwater has become a matter of concern in Ukraine over the last few decades.Actual scientific researches and issues analysis. Recent publications in open access were taken into consideration, including literature on the main methods of purification of water from heavy metal ions.Uninvestigated parts of general matters defining. Information on the sorption purification and after-treatment effectiveness of natural water.The research objective. In this work, the results of the study of the processes of sorption purification of water from heavy metal ions are presented. Samples of magnetite obtained at a ratio of concentrations of iron ions (II) and iron (III) 1:2; 1:1 and 2:1, and the samples modified with sodium sulfide were used as the sorbents.The statement of basic materials. It was shown that the sorption capacity of magnetite towards heavy metal ions increases with the increasing in ratio of [Fe2+]/[Fe3+] from 1:2 to 2:1. The influence of the pH of the medium on the sorption efficiency of heavy metal ions on magnetite was investigated. It was shown that the sorption capacity of magnetite increases with the increasing of pH of the medium, due to the partial hydrolysis of heavy metal ions. Conclusions. Sorption technologies have high efficiency and can be used at different stages of water treatment. Improvement of the sorption capacity of magnetite occurs when modified it with guanidine, thiosemicarbazide and sodium sulfide, which allows to reduce the residual concentrations of heavy metals ions to µg/dm.

The analysis of the scour processes following the pile driving procedures in offshore wind platforms is one of the major problems associated with this new form of clean energy generation. At present there are no scaled studies carried out analyzing the mechanical and deformational behavior of both the material of which the pile supporting the engine and the wind shovels is made (large steel hollow piles with a diameter of 8 m and a thickness of 15–20 cm) as well as the soil where the pile is driven. Usually these elements are installed on a very low granulometry sand displaced from the limits of dry beach– wet beach towards the offshore limits and where, due to this, it cannot return back to its natural state in its previous location. In addition, the few scaled studies carried out on dry soil similar to the existing one in the area of installation of the turbines has not considered a fundamental aspect such as the presence of seawater. This paper presents results obtained from tests to analyze the behavior of the base material on which the turbines are installed (degraded sands). These tests are the direct shear testing and a modification of the California bearing ratio (CBR) test to be carried out on completely submerged samples. The objective is to compare the results with those obtained in standard tests and analyze their suitability for field studies in offshore windfarms.

The analysis of the scour processes following the pile driving procedures in offshore wind platforms is one of the major problems associated with this new form of clean energy generation. At present there are no scaled studies carried out analyzing the mechanical and deformational behavior of both the material of which the pile supporting the engine and the wind shovels is made (large steel hollow piles with a diameter of 8 m and a thickness of 15–20 cm) as well as the soil where the pile is driven. Usually these elements are installed on a very low granulometry sand displaced from the limits of dry beach– wet beach towards the offshore limits and where, due to this, it cannot return back to its natural state in its previous location. In addition, the few scaled studies carried out on dry soil similar to the existing one in the area of installation of the turbines has not considered a fundamental aspect such as the presence of seawater. This paper presents results obtained from tests to analyze the behavior of the base material on which the turbines are installed (degraded sands). These tests are the direct shear testing and a modification of the California bearing ratio (CBR) test to be carried out on completely submerged samples. The objective is to compare the results with those obtained in standard tests and analyze their suitability for field studies in offshore windfarms.

20 subjects were enrolled in this study. 10 were treated with: apically repositioned flap technique (control group) and 10 with modified apically repositioned flap technique (experimental group). The width of attached gingiva, keratinized gingiva, probing pocket depth and gingival recession is measured at day 0 and at 3 months postoperatively on the mid-buccal aspect of the treated teeth. Statistical analysis was performed using 't' test.Significant increase in width of attached and keratinized gingiva were observed in the groups (p<0.05). The experimental group has shown slight reduction in gingival recession as compared to control group in which gingiyal recession has increased. No significant change in probing pocket depth was found in experimental group. There is slight reduction in probing pocket depth in control group. The experimental and control group is equally effective in incresing the width of attached gingiva. The advantage of modified apically repositioned flap techique is in terms of esthetics as it prevents gingival recession which is commonly seen with apically repositioned flap technique.

20 subjects were enrolled in this study. 10 were treated with: apically repositioned flap technique (control group) and 10 with modified apically repositioned flap technique (experimental group). The width of attached gingiva, keratinized gingiva, probing pocket depth and gingival recession is measured at day 0 and at 3 months postoperatively on the mid-buccal aspect of the treated teeth. Statistical analysis was performed using 't' test.Significant increase in width of attached and keratinized gingiva were observed in the groups (p<0.05). The experimental group has shown slight reduction in gingival recession as compared to control group in which gingiyal recession has increased. No significant change in probing pocket depth was found in experimental group. There is slight reduction in probing pocket depth in control group. The experimental and control group is equally effective in incresing the width of attached gingiva. The advantage of modified apically repositioned flap techique is in terms of esthetics as it prevents gingival recession which is commonly seen with apically repositioned flap technique.

Predictive methodologies based on group contribution methods, such as UNIFAC, play a very important role in the design, analysis and optimization of separation processes found in oils, fats and biodiesel industries. However, the UNIFAC model has well-known limitations for complex molecular structures that the first-order functional groups are unable to handle. In the particular case of fatty systems these models are not able to adequately predict the non-ideality in the liquid phase. Consequently, a new set of functional groups is proposed to represent the lipid compounds, requiring thereby, new group interaction parameters. In this work, the performance of several UNIFAC variants, the Original-UNIFAC, the Linear-UNIFAC, Modified-UNIFAC and the Dortmund-UNIFAC is compared. The same set of experimental data and the parameter estimation method developed by Perederic et al. (2017) have been used. The database of measured data comes from a special lipids database developed in-house (SPEED Lipids database at KT-consortium, DTU, Denmark). All UNIFAC models using the new lipid-based parameters show, on average, improvements compared to the same models with their published parameters. There are rather small differences between the models and no single model is the best in all cases.

Adsorbents based on aluminium, zirconium and titanium oxides sequentially modified with polyhexamethylene guanidine (PHMG) and bathocuproinedisulfonic acid (Batocuprsulfo) were proposed for the adsorptionphotometric and test-determination of copper in the variant of test tubes. An effective reagent fixation on the surface of inorganic oxides preliminarily modified with PHMG was attained in the range of pH 3-7. The adsorption capacity of the adsorbents for Batocuprsulfo was 22, 11, 7 μmol/g for Al2O3, ZrO2, and TiO2, respectively. Complex compound of Cu(I) with Batocuprsulfo and stoichiometry Cu:Batocuprsulfo=1:2 was formed on the adsorbents surface during Cu(II) adsorption in the presence of reducing agent – hydroxylamine; it was orange colored with maximum at 490 nm in the diffuse reflectance spectra. The quantitative extraction of Cu(I) and the maximum intensity of the surface color of Cu(I) complex was attained from the solutions with pH 6.0–7.0. This effect was used for developing the procedures for adsorption-photometric determination of Cu(I). The most sensitive procedure used aluminium oxide as an adsorbent matrix. The detection limit of Cu(I) determination calculated by the 3s-criterion was 0.02 μg/0.1 g of the adsorbent. The calibration curves were linear over the range of 0.1 - 15.0 μg/0.1 g. The test-procedure for determination of copper by the length of colored area was developed. The minimum determined concentration of copper was 2 μg/L. The proposed methods were used for the determination of Cu(I) in mineral and natural waters. The results obtained were confirmed by the added−found method, and the results of atomic-emission method with inductively coupled plasma., Для сорбционно-фотометрического и тест-определения меди в варианте индикаторных трубок предложены сорбенты на основе оксидов алюминия, циркония и титана, последовательно модифицированных полигексаметиленгуанидином (ПГМГ) и батокупроиндисульфокислотой (Batocuprsulfo). Эффективное закрепление реагента на поверхности неорганических оксидов, предварительно модифицированных ПГМГ, достигается в диапазоне рН = 3.0-7.0. Максимальная поверхностная концентрация Batocuprsulfo на поверхности неорганических оксидов, модифицированных ПГМГ, составляет 22, 11 и 7 мкмоль/г для Al2O3, ZrO2 и TiO2 соответственно. При сорбции Cu(II) в присутствии восстановителя (гидроксиламина гидрохлорида) на поверхности сорбентов образуется комплекс Cu(I) : Batocuprsulfo = 1 : 2, имеющий оранжевую окраску и максимум при 490 нм в спектрах диффузного отражения. Количественное извлечение Cu(I) неорганическими оксидами, модифицированными ПГМГ и Batocuprsulfo, достигается из растворов с рН = 6.0-7.0 и не зависит от природы матрицы сорбента. Максимальная интенсивность окраски поверхностного комплекса Cu(I) сохраняется в диапазоне рН = 6.0-7.0. Образование окрашенных комплексов Cu(I) на поверхности сорбентов использовано при разработке методик его сорбционно-фотометрического определения с использованием спектроскопии диффузного отражения. Наибольшей чувствительностью характеризуется методика с использованием в качестве матрицы сорбента оксида алюминия. Предел обнаружения Cu(I), рассчитанный по 3s-критерию, равен 0.02 мкг/0.1 г сорбента. Линейность градуировочного графика сохраняется в диапазоне 0.1-15.0 мкг Cu на 0.1 г сорбента. С использованием оксида алюминия, модифицированного ПГМГ и Batocuprsulfo, в качестве тест-системы разработана методика тестопределения меди в природных водах по длине окрашенной зоны с минимально определяемой концентрацией меди 2 мкг/л. Правильность методик подтверждена методом «введено-найдено» и сопоставлением с результатами, полученными независимым методом – АЭС-ИСП.

A variety of charge extraction (CE) techniques have been developed to measure charge density and recombination coefficients in bulk heterojunction solar cells. Charge recombination during charge extraction as a major limitation of this method has not been systematically quantified. This study reports CE measurements using a newly designed fast switch, which enables the application of a reverse bias to the solar cells facilitating charge extraction. With applied reverse bias, more than 40% increase in the extracted charge is obtained in solar cells with thicker active layers or with fast recombination. The measured charge carrier lifetime increases by up to a factor of three at sufficiently high applied biases (up to 8 V), suggesting significant errors in CE measurements without applied bias. The increased extracted charges with increasing applied bias are attributed to a combination of three cases: (i) slightly faster charge extraction due to the larger electric field; (ii) increased charge extraction rate at high light intensities when the transients are space charge disturbed; (iii) increased charge separated lifetime during charge extraction attributed to the spatial separation of the electron and hole density due to the applied electric field.

A variety of charge extraction (CE) techniques have been developed to measure charge density and recombination coefficients in bulk heterojunction solar cells. Charge recombination during charge extraction as a major limitation of this method has not been systematically quantified. This study reports CE measurements using a newly designed fast switch, which enables the application of a reverse bias to the solar cells facilitating charge extraction. With applied reverse bias, more than 40% increase in the extracted charge is obtained in solar cells with thicker active layers or with fast recombination. The measured charge carrier lifetime increases by up to a factor of three at sufficiently high applied biases (up to 8 V), suggesting significant errors in CE measurements without applied bias. The increased extracted charges with increasing applied bias are attributed to a combination of three cases: (i) slightly faster charge extraction due to the larger electric field; (ii) increased charge extraction rate at high light intensities when the transients are space charge disturbed; (iii) increased charge separated lifetime during charge extraction attributed to the spatial separation of the electron and hole density due to the applied electric field.

A variety of charge extraction (CE) techniques have been developed to measure charge density and recombination coefficients in bulk heterojunction solar cells. Charge recombination during charge extraction as a major limitation of this method has not been systematically quantified. This study reports CE measurements using a newly designed fast switch, which enables the application of a reverse bias to the solar cells facilitating charge extraction. With applied reverse bias, more than 40% increase in the extracted charge is obtained in solar cells with thicker active layers or with fast recombination. The measured charge carrier lifetime increases by up to a factor of three at sufficiently high applied biases (up to 8 V), suggesting significant errors in CE measurements without applied bias. The increased extracted charges with increasing applied bias are attributed to a combination of three cases: (i) slightly faster charge extraction due to the larger electric field; (ii) increased charge extraction rate at high light intensities when the transients are space charge disturbed; (iii) increased charge separated lifetime during charge extraction attributed to the spatial separation of the electron and hole density due to the applied electric field.

A variety of charge extraction (CE) techniques have been developed to measure charge density and recombination coefficients in bulk heterojunction solar cells. Charge recombination during charge extraction as a major limitation of this method has not been systematically quantified. This study reports CE measurements using a newly designed fast switch, which enables the application of a reverse bias to the solar cells facilitating charge extraction. With applied reverse bias, more than 40% increase in the extracted charge is obtained in solar cells with thicker active layers or with fast recombination. The measured charge carrier lifetime increases by up to a factor of three at sufficiently high applied biases (up to 8 V), suggesting significant errors in CE measurements without applied bias. The increased extracted charges with increasing applied bias are attributed to a combination of three cases: (i) slightly faster charge extraction due to the larger electric field; (ii) increased charge extraction rate at high light intensities when the transients are space charge disturbed; (iii) increased charge separated lifetime during charge extraction attributed to the spatial separation of the electron and hole density due to the applied electric field.

A variety of charge extraction (CE) techniques have been developed to measure charge density and recombination coefficients in bulk heterojunction solar cells. Charge recombination during charge extraction as a major limitation of this method has not been systematically quantified. This study reports CE measurements using a newly designed fast switch, which enables the application of a reverse bias to the solar cells facilitating charge extraction. With applied reverse bias, more than 40% increase in the extracted charge is obtained in solar cells with thicker active layers or with fast recombination. The measured charge carrier lifetime increases by up to a factor of three at sufficiently high applied biases (up to 8 V), suggesting significant errors in CE measurements without applied bias. The increased extracted charges with increasing applied bias are attributed to a combination of three cases: (i) slightly faster charge extraction due to the larger electric field; (ii) increased charge extraction rate at high light intensities when the transients are space charge disturbed; (iii) increased charge separated lifetime during charge extraction attributed to the spatial separation of the electron and hole density due to the applied electric field.

Neural electrodes have been coated with electrodeposited poly-3,4-ethylenedioxythiophene doped with chondroitin sulphate. Optical and electrochemical methods were used to determine the effective electrode area, charge injection capacity and charge density of the modified electrodes. Deposition times of 15 to 60 s slightly increased the geometric and steady state diffusion electroactive areas while the linear diffusion electroactive area grew significantly, indicating an increase in electrode roughness. The effective electrode area and charge injection capacity were significantly smaller than PEDOT doped with previously tested dopants. In contrast to other dopant ions, the charge density determined from the geometric and steady state diffusion electroactive areas was nearly constant with increased deposition time while the linear diffusion charge density decreased.

Neural electrodes have been coated with electrodeposited poly-3,4-ethylenedioxythiophene doped with chondroitin sulphate. Optical and electrochemical methods were used to determine the effective electrode area, charge injection capacity and charge density of the modified electrodes. Deposition times of 15 to 60 s slightly increased the geometric and steady state diffusion electroactive areas while the linear diffusion electroactive area grew significantly, indicating an increase in electrode roughness. The effective electrode area and charge injection capacity were significantly smaller than PEDOT doped with previously tested dopants. In contrast to other dopant ions, the charge density determined from the geometric and steady state diffusion electroactive areas was nearly constant with increased deposition time while the linear diffusion charge density decreased.

This study aims to characterize anaerobically digested sludge (ADS) and correlate the sludge characteristics in terms of soluble organic compounds with polymer demand (PD) during sludge conditioning. The PD required to achieve maximum dewatering of the ADS studied is in the range of 8-10 kg polymer/dry ton. The commonly used capillary suction time parameter to evaluate the solid-liquid separation ability was not a reliable indicator for assessing dewatering. Instead, in this study, a modified centrifugal technique proposed by Higgins (Higgins MCT) was used to assess the maximum achievable dry solids content of the biosolids cake. The Higgins MCT is readily obtained using a bench-scale centrifuge equipped with a modified centrifuge bucket. Using the Higgins MCT, the maximum dry solids contents obtained from conditioned ADS was 30 wt%. These values were comparable to the dry solids content obtained from the same sludge at full-scale level. Our results suggest Higgins MCT is suitable for assessing the final dry solids content and simulating the dewatering process.

In this paper, a small remote area which is located in Nigeria has been considered as a model to be tested by a managing scheme for providing both electricity and water. In this strategy, the groundwater is pumped into a water tank which can be later used for supplying required irrigation and drinking water. A PAT (Pump as Turbine) is used as a hybrid system for supplying electricity and water as well as storing water in the water tank. Also, a PV (photovoltaic plant), a package of batteries (BAT) in addition to a diesel ICE (internal combustion engine) are used and optimized along with the best size of devices and managing system, with the purpose of obtaining the maximum economical operating strategy. In this paper, two cases are considered to assess the effectiveness of the system under study. Firstly, all of the mentioned devices are used to show how internal combustion engine system dominates all the other components due to the low cost of fuel. In the second case, all renewable resources have been exploited and optimized in order to make a 100% renewable system with least possible cost. Having about 53 variables makes this problem very complicated which requires to be solved by an algorithm with more accuracy. Therefore, a MGSA (Modified Gravitational Search Algorithm) with an adapted mutation tactic is used to find the best cost and management strategy. In the first case, although the cost of diesel oil is very low, by using the PAT, about 5% of diesel oil consumption is reduced. In the second case, in order to make a 100% renewable system, the size of PV is enlarged approximately 16 times in comparison with the first case. The hybrid PV-PAT storing structure is capable to deliver the water for irrigation and domestic requirements as well as 9% of the electricity needed for the rural community.

The impedance of electrodes at 1 kHz is typically reported to assess the signal-to-noise ratio of neural recording electrodes. The impedance response of platinum electrodes modified by poly-3,4-ethylenedioxythiophene doped with dextran sulfate has been examined. The modified electrodes have lower impedance at low and intermediate frequencies compared to unmodified electrodes. The impedance and phase angle at low frequencies is strongly correlated with the electrode area. The geometric and linear diffusion charge densities of the modified electrodes are also dependent on the electrode area and impedance at low frequencies. A 3 time constant equivalent circuit provided a better fit to the impedance than a 2 time constant model. The decrease in impedance at low frequencies indicates PEDOT-DS will be suitable for reducing the thermal noise and increasing the signal-to-noise ratio for neural recording electrodes.

Neural electrodes have been coated with electrodeposited poly-3,4-ethylenedioxythiophene doped with chondroitin sulphate. Optical and electrochemical methods were used to determine the effective electrode area, charge injection capacity and charge density of the modified electrodes. Deposition times of 15 to 60 s slightly increased the geometric and steady state diffusion electroactive areas while the linear diffusion electroactive area grew significantly, indicating an increase in electrode roughness. The effective electrode area and charge injection capacity were significantly smaller than PEDOT doped with previously tested dopants. In contrast to other dopant ions, the charge density determined from the geometric and steady state diffusion electroactive areas was nearly constant with increased deposition time while the linear diffusion charge density decreased.

Emerald Group Publishing Limited.Purpose - The purpose of this paper is to explore the applicability of the Australasian Therapeutic Communities Association (ATCA) Standard to Australian youth-specific modified therapeutic communities (MTCs). An Interpretive Guide for Youth MTCs and Residential Rehabilitation (RR) Services was developed and a pilot trial conducted with three Australian youth MTC services. Design/methodology/approach - Using a mixed-methods design, this study included three components: a consultation process with residential youth MTCs (N=15), which informed the development of the ATCA Standard Interpretive Guide for Youth MTCs and RR Services; a pilot trial of the materials with three Australian youth MTCs (N=53); and an evaluation of the interpretive guide and assessment of applicability of the ATCA standard to youth MTCs through pre- (N=32) and post- (N=19) pilot trial administrations of the Survey of Essential Elements Questionnaires (SEEQ), and post-pilot trial focus groups (N=21). Findings - Results indicate that the ATCA Standard is applicable to youth MTC settings when applied with the Interpretive Guide, although no significant differences were found between the pre- and post-pilot trial administrations of the SEEQ. Practical implications - Future research is recommended to explore active mechanisms of youth-specific MTCs, differences between adults and youth MTCs, and the development of TC-specific training. Originality/value - To date, no standard for youth residential substance use services in Australia has been developed, and this is the first study of its kind internationally to explore the efficacy of standards in a youth MTC.

The optical sensing of iron(II) based on the chromophore, (E) 4′-(2-(4,4″-bisdecyloxy-2,2′:5′,2″-terthiophen-3′-yl)ethenyl)-2,2′:6′,2"-terpyridine, incorporated in a plasticized poly(vinyl chloride) matrix was studied. The chromophore was obtained by the chemical modification of terpyridine with a terthiophene derivative. This modification not only enhanced the application of terpyridyl iron(II) sensing as a result of reduced aqueous solubility but also enhanced the optical sensitivity of the chromophore and greatly influenced the kinetics of ligand metal interactions by decelerating the complex formation between iron(II) and the terpyridine. This latter feature allowed the exploration of novel spectroscopic methods of Fe2+ analysis based on concentration- and time-dependent complexation of iron(II) by the chromophore. Membranes containing the chromophore were deposited on glass and paper strips and studied further as disposable iron(II)-sensitive sensors. Kinetic-based methods of ion analysis were developed by employing absorbance measurements. This report presents the possibility of chemical modification of the complexing agents in order to decelerate the kinetics of their complex formation with the analyte, thus allowing a novel type of optical ion sensing.

The impedance of electrodes at 1 kHz is typically reported to assess the signal-to-noise ratio of neural recording electrodes. The impedance response of platinum electrodes modified by poly-3,4-ethylenedioxythiophene doped with dextran sulfate has been examined. The modified electrodes have lower impedance at low and intermediate frequencies compared to unmodified electrodes. The impedance and phase angle at low frequencies is strongly correlated with the electrode area. The geometric and linear diffusion charge densities of the modified electrodes are also dependent on the electrode area and impedance at low frequencies. A 3 time constant equivalent circuit provided a better fit to the impedance than a 2 time constant model. The decrease in impedance at low frequencies indicates PEDOT-DS will be suitable for reducing the thermal noise and increasing the signal-to-noise ratio for neural recording electrodes.

Neural electrodes have been coated with electrodeposited poly-3,4-ethylenedioxythiophene doped with chondroitin sulphate. Optical and electrochemical methods were used to determine the effective electrode area, charge injection capacity and charge density of the modified electrodes. Deposition times of 15 to 60 s slightly increased the geometric and steady state diffusion electroactive areas while the linear diffusion electroactive area grew significantly, indicating an increase in electrode roughness. The effective electrode area and charge injection capacity were significantly smaller than PEDOT doped with previously tested dopants. In contrast to other dopant ions, the charge density determined from the geometric and steady state diffusion electroactive areas was nearly constant with increased deposition time while the linear diffusion charge density decreased.

Neural electrodes have been coated with electrodeposited poly-3,4-ethylenedioxythiophene doped with chondroitin sulphate. Optical and electrochemical methods were used to determine the effective electrode area, charge injection capacity and charge density of the modified electrodes. Deposition times of 15 to 60 s slightly increased the geometric and steady state diffusion electroactive areas while the linear diffusion electroactive area grew significantly, indicating an increase in electrode roughness. The effective electrode area and charge injection capacity were significantly smaller than PEDOT doped with previously tested dopants. In contrast to other dopant ions, the charge density determined from the geometric and steady state diffusion electroactive areas was nearly constant with increased deposition time while the linear diffusion charge density decreased.

The optical sensing of iron(II) based on the chromophore, (E) 4′-(2-(4,4″-bisdecyloxy-2,2′:5′,2″-terthiophen-3′-yl)ethenyl)-2,2′:6′,2"-terpyridine, incorporated in a plasticized poly(vinyl chloride) matrix was studied. The chromophore was obtained by the chemical modification of terpyridine with a terthiophene derivative. This modification not only enhanced the application of terpyridyl iron(II) sensing as a result of reduced aqueous solubility but also enhanced the optical sensitivity of the chromophore and greatly influenced the kinetics of ligand metal interactions by decelerating the complex formation between iron(II) and the terpyridine. This latter feature allowed the exploration of novel spectroscopic methods of Fe2+ analysis based on concentration- and time-dependent complexation of iron(II) by the chromophore. Membranes containing the chromophore were deposited on glass and paper strips and studied further as disposable iron(II)-sensitive sensors. Kinetic-based methods of ion analysis were developed by employing absorbance measurements. This report presents the possibility of chemical modification of the complexing agents in order to decelerate the kinetics of their complex formation with the analyte, thus allowing a novel type of optical ion sensing.

The optical sensing of iron(II) based on the chromophore, (E) 4′-(2-(4,4″-bisdecyloxy-2,2′:5′,2″-terthiophen-3′-yl)ethenyl)-2,2′:6′,2"-terpyridine, incorporated in a plasticized poly(vinyl chloride) matrix was studied. The chromophore was obtained by the chemical modification of terpyridine with a terthiophene derivative. This modification not only enhanced the application of terpyridyl iron(II) sensing as a result of reduced aqueous solubility but also enhanced the optical sensitivity of the chromophore and greatly influenced the kinetics of ligand metal interactions by decelerating the complex formation between iron(II) and the terpyridine. This latter feature allowed the exploration of novel spectroscopic methods of Fe2+ analysis based on concentration- and time-dependent complexation of iron(II) by the chromophore. Membranes containing the chromophore were deposited on glass and paper strips and studied further as disposable iron(II)-sensitive sensors. Kinetic-based methods of ion analysis were developed by employing absorbance measurements. This report presents the possibility of chemical modification of the complexing agents in order to decelerate the kinetics of their complex formation with the analyte, thus allowing a novel type of optical ion sensing.

The impedance of electrodes at 1 kHz is typically reported to assess the signal-to-noise ratio of neural recording electrodes. The impedance response of platinum electrodes modified by poly-3,4-ethylenedioxythiophene doped with dextran sulfate has been examined. The modified electrodes have lower impedance at low and intermediate frequencies compared to unmodified electrodes. The impedance and phase angle at low frequencies is strongly correlated with the electrode area. The geometric and linear diffusion charge densities of the modified electrodes are also dependent on the electrode area and impedance at low frequencies. A 3 time constant equivalent circuit provided a better fit to the impedance than a 2 time constant model. The decrease in impedance at low frequencies indicates PEDOT-DS will be suitable for reducing the thermal noise and increasing the signal-to-noise ratio for neural recording electrodes.

In this manuscript, an interesting phenomenon is reported. That is the self-growth of single crystals in Pb-free piezoelectric ceramics. These crystals are several centimeters in size. They are grown without any seed addition through a normal sintering process in modified potassium sodium niobate ceramics. It has been achieved by the composition designed to compensate the Na + loss which occurs during the liquid phase sintering. The composition of the crystals is (K0.4925 Na0.4925-x Ba0.015+x/2)Nb 0.995+x O3 [x is determined by the Na+ loss, due to Na2O volatilization]. These crystals have high piezoelectric voltage coefficients (g33, 131 10-3 Vm/N), indicating that they are good candidates for piezoelectric sensors and energy harvesting devices. We hope that this report can offer the opportunity for many researchers to have an interest in these crystals.

Graphene, honeycomb structure of carbon having exceptional characteristics have attracted researcher's interest and is now being studied and used in numerous technological areas and next generation nano devices. In this research work, reduced graphene oxide was functionalized with magnetic nano crystals, i.e. ZnFe2O4 via modified solvothermal approach. X-ray diffraction and Micro Raman spectroscopy was used to confirm structural aspects of synthesized graphene oxide and ZnFe2O4 pristine magnetic nano crystals and the functionalized rGO-ZnFe2O4 nano hybrid. Morphology were analyzed through SEM showing that the particles sizes were in between 24 and 27 nm range attached to reduced graphene oxide sheets while composition and valence state of functional groups were analyzed through XPS. UV-Vis spectroscopy was carried out for analyzing their optical absorption behavior. Their optical characteristics were explained in depth in relation with their structural aspects and functionalization behavior.

The aim of the present study is to investigate the geometrically nonlinear size-dependent bending as well as resonant behaviour over the bent state of a microarch under an axial load. In particular, an axial load is applied on the system causing the initial curvature to increase by giving rise to a new bent configuration. A distributed harmonic transverse force is then exerted on the microarch and the nonlinear resonant response of the system over the new deflected configuration is investigated. The nonlinear partial differential equation of motion is obtained via Hamilton's principle based on the modified couple stress theory. The equation is discretized into a set of nonlinear ordinary differential equations through use of the Galerkin scheme. The pseudo-arclength continuation technique is then applied to the resultant set of ordinary differential equations. First, for the unforced system in the transverse direction, the axial load is increased and the new deflected configuration of the system is plotted versus the axial compression load; the nonlinear resonant response over the deflected configuration is then investigated through constructing frequency-response and force-response curves.

The nonlinear dynamical behaviour of a geometrically imperfect microplate is examined based on the modified couple stress theory. The microplate is modelled by means of the von Kármán plate theory and Kirchhoff's hypotheses retaining all in-plane and out-of-plane displacements and inertia. An initial imperfection in the out-of-plane direction is taken into account and the equations of motion for the in-plane and out-of-plane motions are obtained by means of an energy method based on the Lagrange equations. This operation gives three sets of second-order nonlinear ordinary differential equations with coupled terms for two in-plane motions and one out-of-plane motion. These sets are transformed into double-dimensional sets of first-order nonlinear ordinary differential equations which are solved numerically through use of a continuation technique. Apart from the nonlinear analysis, an eigenvalue analysis is also conducted to obtain the linear natural frequencies of the system with different amplitudes of the geometric imperfection. The effect of the amplitude of the geometric imperfection and thickness of the microplate as well as the forcing frequency on the response of the system is highlighted. Finally, a comparison is made between the responses of the system based on the modified couple stress and classical continuum mechanics theories so as to highlight the importance of taking into account small-size effects.

The nonlinear dynamical behaviour of a geometrically imperfect microplate is examined based on the modified couple stress theory. The microplate is modelled by means of the von Kármán plate theory and Kirchhoff's hypotheses retaining all in-plane and out-of-plane displacements and inertia. An initial imperfection in the out-of-plane direction is taken into account and the equations of motion for the in-plane and out-of-plane motions are obtained by means of an energy method based on the Lagrange equations. This operation gives three sets of second-order nonlinear ordinary differential equations with coupled terms for two in-plane motions and one out-of-plane motion. These sets are transformed into double-dimensional sets of first-order nonlinear ordinary differential equations which are solved numerically through use of a continuation technique. Apart from the nonlinear analysis, an eigenvalue analysis is also conducted to obtain the linear natural frequencies of the system with different amplitudes of the geometric imperfection. The effect of the amplitude of the geometric imperfection and thickness of the microplate as well as the forcing frequency on the response of the system is highlighted. Finally, a comparison is made between the responses of the system based on the modified couple stress and classical continuum mechanics theories so as to highlight the importance of taking into account small-size effects.

The aim of the present study is to investigate the geometrically nonlinear size-dependent bending as well as resonant behaviour over the bent state of a microarch under an axial load. In particular, an axial load is applied on the system causing the initial curvature to increase by giving rise to a new bent configuration. A distributed harmonic transverse force is then exerted on the microarch and the nonlinear resonant response of the system over the new deflected configuration is investigated. The nonlinear partial differential equation of motion is obtained via Hamilton's principle based on the modified couple stress theory. The equation is discretized into a set of nonlinear ordinary differential equations through use of the Galerkin scheme. The pseudo-arclength continuation technique is then applied to the resultant set of ordinary differential equations. First, for the unforced system in the transverse direction, the axial load is increased and the new deflected configuration of the system is plotted versus the axial compression load; the nonlinear resonant response over the deflected configuration is then investigated through constructing frequency-response and force-response curves.

In this manuscript, an interesting phenomenon is reported. That is the self-growth of single crystals in Pb-free piezoelectric ceramics. These crystals are several centimeters in size. They are grown without any seed addition through a normal sintering process in modified potassium sodium niobate ceramics. It has been achieved by the composition designed to compensate the Na + loss which occurs during the liquid phase sintering. The composition of the crystals is (K0.4925 Na0.4925-x Ba0.015+x/2)Nb 0.995+x O3 [x is determined by the Na+ loss, due to Na2O volatilization]. These crystals have high piezoelectric voltage coefficients (g33, 131 10-3 Vm/N), indicating that they are good candidates for piezoelectric sensors and energy harvesting devices. We hope that this report can offer the opportunity for many researchers to have an interest in these crystals.

Graphene, honeycomb structure of carbon having exceptional characteristics have attracted researcher's interest and is now being studied and used in numerous technological areas and next generation nano devices. In this research work, reduced graphene oxide was functionalized with magnetic nano crystals, i.e. ZnFe2O4 via modified solvothermal approach. X-ray diffraction and Micro Raman spectroscopy was used to confirm structural aspects of synthesized graphene oxide and ZnFe2O4 pristine magnetic nano crystals and the functionalized rGO-ZnFe2O4 nano hybrid. Morphology were analyzed through SEM showing that the particles sizes were in between 24 and 27 nm range attached to reduced graphene oxide sheets while composition and valence state of functional groups were analyzed through XPS. UV-Vis spectroscopy was carried out for analyzing their optical absorption behavior. Their optical characteristics were explained in depth in relation with their structural aspects and functionalization behavior.

The aim of the present study is to investigate the geometrically nonlinear size-dependent bending as well as resonant behaviour over the bent state of a microarch under an axial load. In particular, an axial load is applied on the system causing the initial curvature to increase by giving rise to a new bent configuration. A distributed harmonic transverse force is then exerted on the microarch and the nonlinear resonant response of the system over the new deflected configuration is investigated. The nonlinear partial differential equation of motion is obtained via Hamilton's principle based on the modified couple stress theory. The equation is discretized into a set of nonlinear ordinary differential equations through use of the Galerkin scheme. The pseudo-arclength continuation technique is then applied to the resultant set of ordinary differential equations. First, for the unforced system in the transverse direction, the axial load is increased and the new deflected configuration of the system is plotted versus the axial compression load; the nonlinear resonant response over the deflected configuration is then investigated through constructing frequency-response and force-response curves.

The nonlinear dynamical behaviour of a geometrically imperfect microplate is examined based on the modified couple stress theory. The microplate is modelled by means of the von Kármán plate theory and Kirchhoff's hypotheses retaining all in-plane and out-of-plane displacements and inertia. An initial imperfection in the out-of-plane direction is taken into account and the equations of motion for the in-plane and out-of-plane motions are obtained by means of an energy method based on the Lagrange equations. This operation gives three sets of second-order nonlinear ordinary differential equations with coupled terms for two in-plane motions and one out-of-plane motion. These sets are transformed into double-dimensional sets of first-order nonlinear ordinary differential equations which are solved numerically through use of a continuation technique. Apart from the nonlinear analysis, an eigenvalue analysis is also conducted to obtain the linear natural frequencies of the system with different amplitudes of the geometric imperfection. The effect of the amplitude of the geometric imperfection and thickness of the microplate as well as the forcing frequency on the response of the system is highlighted. Finally, a comparison is made between the responses of the system based on the modified couple stress and classical continuum mechanics theories so as to highlight the importance of taking into account small-size effects.

The nonlinear dynamical behaviour of a geometrically imperfect microplate is examined based on the modified couple stress theory. The microplate is modelled by means of the von Kármán plate theory and Kirchhoff's hypotheses retaining all in-plane and out-of-plane displacements and inertia. An initial imperfection in the out-of-plane direction is taken into account and the equations of motion for the in-plane and out-of-plane motions are obtained by means of an energy method based on the Lagrange equations. This operation gives three sets of second-order nonlinear ordinary differential equations with coupled terms for two in-plane motions and one out-of-plane motion. These sets are transformed into double-dimensional sets of first-order nonlinear ordinary differential equations which are solved numerically through use of a continuation technique. Apart from the nonlinear analysis, an eigenvalue analysis is also conducted to obtain the linear natural frequencies of the system with different amplitudes of the geometric imperfection. The effect of the amplitude of the geometric imperfection and thickness of the microplate as well as the forcing frequency on the response of the system is highlighted. Finally, a comparison is made between the responses of the system based on the modified couple stress and classical continuum mechanics theories so as to highlight the importance of taking into account small-size effects.