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The phenomenon of continuous land-use change is common in urban areas, and Kota Jantho is no exception. Kota Jantho has advanced both economically and in terms of development as the regional capital and a city that serves as a center for education in Aceh Besar Regency. The presence of the Indonesian Institute of Cultural Arts (ISBI) Aceh campus, in Kota Jantho, is one of the factors causing changes in land use. Furthermore, a qualitative method was used in this study along with the interactive model data analysis techniques from Miles and Huberman. The data obtained from interviews, observations, and documentations, as well as secondary data from pertinent studies were used to explain the results. Data analysis was conducted by collecting, reducing, and presenting the data, after which conclusions were drawn. Admittedly, the existence of the ISBI Aceh campus in Kota Jantho has significantly increased the population in the area, and this influenced the continuous increase in demands for goods. This land's designation was changed by constructing the campus and this means that the allotment of land which was once unproductive was changed to become more productive by incorporating social economic activities such as housing development, trades, services, tourism, and agriculture. Additionally, the construction of the Campus has significantly influenced changes in the land use of Kota Jantho, which has become a service hub for local businesses and a place where trades and services had grown significantly. [ABSTRACT FROM AUTHOR]

Chemistry plays an essential role in human life, especially in teaching and learning; however, only a few studies offer an up-to-date and comprehensive overview of chemistry education research (CER) using quantitative bibliometric analysis. For this purpose, the current study explores the trends and status of research in chemistry education over time. A total of 4110 peer-reviewed journal articles were retrieved from the Scopus database. The number of publications in CER demonstrates a significantly increasing pattern from 1895 to 2022. The most frequently cited articles belong to Black and Deci, Hartinger and Dyson, and Baepler et al., Journal of Chemical Education, Chemistry Education Research and Practice, and International Journal of Science Education are the most productive journals. The most prominent institutions are Purdue University, Universitat Bremen, and the University of South Florida. The US, Turkey, and Germany stand out in the number of publications. I. Eilks, V. Talanquer, and M.M. Cooper lead the top three authors with the most publications. The most frequently used author keywords are "first-year undergraduate", "chemistry education", and "upper-division undergraduate". The current study provides a holistic understanding of the development of CER and a reference for future studies in the field. [ABSTRACT FROM AUTHOR]

For Muslims, prayer is worship that becomes a benchmark for charity, which means that the quality of a person's charity is determined by his prayer and by reciting the Qur'an. An understanding of the importance and obligation of worship needs to be instilled in students. Apart from the obligatory prayers and reciting the Qur'an, which is usually done, the sunnah prayers (not mandatory but better if done) are not necessarily a worship routine. This study aims to reveal the effect of the intensity of reciting the Qur'an on students' sunnah prayers. This study uses a simple linear regression supervised learning algorithm to see the impact of monthly Qur'an reading intervals on students' monthly sunnah worship. Data were collected by surveying students. The analysis in this study uses the independent variable, namely the interval for reciting the Qur'an, and the dependent variable, namely the number of night (Tahajud) prayers and Dhuha prayers. The results and experiments of this research are divided into two models: the comparison of reciting the Qur'an to the night (Tahajud) prayers and the comparison of reciting the Qur'an to the Dhuha prayer. The resulting model has an accuracy of 90.32% for predictions of night (Tahajud) prayers and 85.73% for predictions of Dhuha prayers. The results of this study indicate that the higher the interval of reciting the Qur'an, the higher the sunnah worship carried out by students. [ABSTRACT FROM AUTHOR]

Climate change threatens health and death. Climate change creates vulnerability for regions and communities due to increased vector-related diseases, water-related diseases and socio-economic problems. One of the efforts to anticipate climate change is vulnerability mapping. Study aims to map the health vulnerability due to climate change in Indonesia's West Sumatra Province. Vulnerability assessment using exposure and sensitivity elements to the adaptability of the community, the form of indicators/parameters in all districts and cities of West Sumatra, Indonesia. The regional vulnerability assessment indicate that agricultural areas are more vulnerable than coastal areas. The community vulnerability assessment show that exposure occurs in high population density, rainfall, and dengue cases. Sensitivity occurs due to lack of livelihoods and access to clean water. Adaptive capacity occurs due to a lack of gender equality and healthy living behavior. It needs early awareness of disease due to changes in environmental improvements in each region. [ABSTRACT FROM AUTHOR]

Photopolymerization of product blending methyl methacrylate with reactive mesogen RM257 using the UV Curing method with time variations. UV radiation formed a new polymer by adding the Benzoyl Peroxide (BPO) initiator. Polymerization was carried out at a temperature of 120°C in time variations of 5 minutes, 10 minutes, 15 minutes, and 20 minutes. Polymers were characterized using FTIR, SEM, XRD, and LCR Meter. FTIR spectrum showed the absorption peak at 2950 cm−1 indicating–C-H3 bonds, 1721 cm−1 indicating C=O bonds, 1604 cm−1 indicating aromatic functional group, 1248 cm−1 indicating C-O-C bonds, 1144 and 1060 cm−1 indicates of C-O bonds. Morphology analysis by SEM shows that polymer has uniform textures and visible molecular shape of rods. Pattern peaks of XRD appeared at an angle range of 2θ 10°-90°, there was a broad peak at 2θ 10°-38°, the appearance of sharp peaks with moderate intensity at 2θ 13.90° and 16.83°, high intensity appeared at 2θ 44.66°. This pattern XRD indicates that the polymer of product blending is semicrystalline. An LCR meter's measurement conductivities show that the highest conductivity value of a thin film is 2.245 x 10−6 S/cm. [ABSTRACT FROM AUTHOR]

This study aims to develop and determine the effect of using mobile media Learning integrated Learning Management System (LMS) based on Discovery Learning on students' critical thinking skills on Ion Balance and pH of Salt Solutions. The research was carried out at SMA Negeri 92 Jakarta in December 2021 until April 2022. Method The research used is research and development by Borg and Gall with modify five Step, need analysis; development product; validation; testing product; and implementation. To see the influence of Mobile Learning media uses quantitative research with the Quasi Experiment method. The research design used was a nonequivalent control group design. In this study, 2 classes were used, namely class XI MIPA 4 as the experimental class and class XI MIPA 3 as the control class. Hypothesis testing using the Independent-Sample T test. The resulting media output is salt hydrolysis.apk with a file size of 78 MB which is compatible on android devices on smartphone nor tablets and salt hydrolysis.exe with a file size of 35.4 MB for laptop or PC use %. The posttest value of the experimental class was 74.88 while the posttest value of the control class was 69.15. Hypothesis testing on the posttest data obtained the value of Sig. (2-tailed) (0.01) < alpha (0.05) and Tcount (2.633) > TTable (2.024). It can be concluded that H0 rejected and H1 received which means there is influence significant use of Mobile Learning integrated Learning Management System (LMS) based on Discovery Learning on students' critical thinking skills on Ion Equilibrium and pH of Salt Solutions. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the use of the "Go-Chemist!" app on students' perceptions of chemistry, especially on the topic of atomic structure. This study used a quasi-experimental pretest-posttest design. The respondents were 72 students consisting of 42 females and 30 males, at a public high school in Jakarta, Indonesia. They were recruited from 2 intact classes, namely the experimental and control groups, with a total of 36 students each. Students in the experimental group were instructed with the "Go-Chemist!" application, while students in the control group were taught using a printed textbook during the treatment. To collect data, the Perception of Chemistry Questionnaire (PCQ) was completed by all respondents as pre-tests and post-tests to measure changes in their perceptions. Independent and paired sample t-tests were used to check the difference and increase the mean score between the two groups. As a result, students in the experimental group scored higher on perception than students in the control group after the intervention. In addition, students using the mobile app showed a significant improvement in perception compared to their counterparts. Based on the findings, it can be concluded that the "Go-Chemist!" app is effective for elevating students' positive perceptions on the topic of atomic structure. Thus, it is highly recommended for teachers and students to use this mobile app to support teaching and learning chemistry. [ABSTRACT FROM AUTHOR]

This study investigates the effect of using the "Go-Chemist!" on students' self-efficacy regarding chemistry and technology on hydrocarbons. This study used a quasi-experimental pre-test-posttest design. The respondents were 72 students (25 males and 47 females) at a public high school in Jakarta, Indonesia. Students in the experimental group (n = 36) were instructed to use the "Go-Chemist!" app, and students in the control group (n = 36) were taught using printed textbooks. All students in both groups completed the Self-Efficacy Scale towards Science and Technology (SESST) before and after the intervention to measure their level of self-efficacy on the topic of hydrocarbons. Independent and paired sample t-tests were used to analyze the difference and increase in scores between the experimental and control groups. The results reflected that students in the experimental group were superior, and there was a significant increase in the mean score compared to the control group concerning self-efficacy. Based on the findings, we recommend that teachers and students use the "Go-Chemist!" app to promote students' self-efficacy toward chemistry and technology on the topic of hydrocarbons to a satisfactory level. [ABSTRACT FROM AUTHOR]

Unmanned aerial vehicles (UAVs) have recently been suggested as a swift, simple to replicate, and economical way to monitor macro litter. High-resolution UAV imageries were utilised to create ways to identify plastic debris drifting in the river as the initial step in this research. The object-based classification method was used to detect the occurrence of plastic pollution in the Rasau River. This study consists of three objectives; i) to review the use of UAV imageries to detect any form of plastics pollution along Rasau River ii) to examine the visibility of plastics pollution, and iii) to identify the suitable altitude that was used, and effectively visualise the plastic pollution phenomena. The study used two flying altitudes, which are 50 m and 80 m. The data were processed in pix4D Mapper and ArcGIS Pro software. The results of distribution in the identified plastic pollution were presented on maps. The accuracy assessment for this study was made by presenting the final output data for both altitudes. Based on the results, the overall accuracy for 50 m altitude is 92% with 0.881 kappa statistic, while for the 80 m, the overall accuracy of the output is 90% and 0.859 kappa statistic. Meanwhile, the accuracy of plastic pollution at 50 m altitude was 85%, and 80 m was 63%, which showed a significant difference in accuracy percentage. Furthermore, the area covered by plastic pollution at 50 m altitude was 1525.87 m² was greater than 221.38 m² for the 80 m altitude. There was a significant difference in the resulting imageries captured in these two flying altitudes. [ABSTRACT FROM AUTHOR]

In thermochemistry experiments, a large volume and relatively high concentration of chemicals are often used to get a significant temperature change using an analogue thermometer. A 'greener' experimental protocol is developed as an alternative using modern microcontroller boards, ChemDuino. The aim of this research is to develop a low-cost and pocket-sized prototype for measuring temperature of solutions using Arduino Uno R3 DIP and DS18B20 sensor based on green chemistry and DIY (do-it –yourself) methods. The construction of ChemDuino for temperature sensing is made in the simplest manner for individuals with little knowledge of electronics. The details of all components are stipulated in this paper. This research was conducted in three phases, which includes preliminary, prototype development, and assessment phase. The device is used to determine the enthalpy change of neutralization (ΔH) of NaOH and HCƖ solution. The enthalpy change of neutralization, kJ mol−1 at 25.0 °C from literature is −57.13 kJ mol−1, whereas the enthalpy change of neutralization, kJ mol−1 at 25.0 °C from the experiment using ChemDuino-Calorimetry is −56.87 (±1.9) kJ mol−1 (average of seven determinations and estimated standard deviation). The device has successfully measured the temperature change of the reaction at a relatively lower concentration. ChemDuino-Calorimetry has a great potential, because of its reliability and accuracy in measurements, inexpensive setup, and interconnectivity. [ABSTRACT FROM AUTHOR]

The covid 19 pandemic that has hit the world today has brought people's lives in general to the use of internet-based technology. In the midst of the increasing use of the internet and its devices, cyber-crime has also increased. Various cyber-crime have occurred, including computer and internet attacks related to the government's handling of the covid 19 pandemic. However, in the midst of cyber-crime prevention efforts, a polemic has emerged regarding law enforcement, where some views say that there is injustice in law enforcement. Cybercrime is a real problem in the midst of situations and conditions that occurred and requires appropriate law enforcement efforts, but there is hope that the use of criminal law in this matter must be an appropriate effort and policy from the government. This is of course interesting if studied and analyzed through an approach to criminal law policy, where there is approach related to socio political aspects and socio cultural aspects of values approach the main issue in this research is how to law enforcement in tackling cyber-crime during the covid 19 pandemic and strategic policy in overcoming the problem cyber-crime during the covid 19 pandemic. The method used in research is normative juridical with a legal approach and conceptual approach. Descriptive research with qualitative data analysis. This study presents strategic policies in tackling cyber-crime as a negative impact of technological advances that developed during the pandemic so that the use of technological advances, especially with regard to cyber space, can be in line with community needs. Thus, the issues discussed are relevant to the topic of this conference. [ABSTRACT FROM AUTHOR]

Potential of liquid crystals in various applications such as storage devices, microfluidic, optics, flexible electronics, and artificial muscles. This research was conducted by modify of Methyl Methacrylate (MMA) with mesogen reactive of RM82 using UV Curing technique. This research using variations concentration of RM82 which was made varies from 15 wt%, 20 wt%, 25 wt% to 30 wt%. Process UV curing using mixtures solvents of chloroform and dimethylformamide that process on a glass plate and induced by UV light. Product of liquid crystal polymer PMMA-RM82 that resulted this research is a transparent thin film. Characterizations of liquid crystal polymer PMMA-RM82 were Fourier Transformed Infra Red (FTIR) and X Ray Diffractions (XRD). Peaks of FTIR showed that a strong interaction between PMMA and 30% of RM82 which is indicated by the presence of CH3 group vibrations, carbonyl group, C-O ester bond vibration. Peak of XRD showed width peak 2θ in 15 until 25° due to the appearance of soft crystalline segments and two high intensity crystallinity peaks at 2θ is 15,97° and 2θ is 18,59° when 30 wt% of RM82 was added. The addition 30 wt% of RM82 showed the occurrence of cross-linked nematic phase in the liquid crystal polymer PMMA-RM82. The SEM results showed that liquid crystal polymer PMMA-RM82 had a rice grain-like morphology according to short mesogenic monomer with and without flexible spacers. [ABSTRACT FROM AUTHOR]

Research about the manufacture of polyeugenol/ZnO composite materials was carried out with ratios: 100:0 75:25 50:50 25:75 and 0:100 (w/w; mg/mg). Polyeugenol was synthesized from eugenol compound using H2SO4-CH3COOH catalyst. The addition of ZnO could show much stronger antibacterial properties compared to polyeugenol. The reason for this research was to decide the proportion of the polyeugenol/ZnO composite material which has the most grounded antibacterial action against Escherichia coli and Staphylococcus aureus microorganisms. The strategy for deciding antibacterial properties was a good dissemination technique by noticing the distance across the restraint zone. The data obtained were analyzed through variance methods (ANOVA) and post-hoc tests by Duncan. The comparison showed the largest inhibition zone diameter of 19.76 mm for S.aureus and 20.29 mm for E.coli (polyeugenol 75 mg : ZnO 25 mg). [ABSTRACT FROM AUTHOR]

This ex post facto study aimed to describe the impact of motivation and independence of learning on students' mathematics learning outcomes. The research sample consisted of 49 students of SMA UNP Laboratory Development, who were selected purposively. The research data was collected through the provision of motivation and learning independence questionnaires and mathematics tests. A multiple linear regression test was conducted to analyze the collected data. The result indicates that learning motivation and learning independence have on students' outcomes in mathematics, either individually or together. Of all students with high learning motivation, only 20% of students have high mathematics learning outcomes, meanwhile for students with low learning motivation, only 4% of students whose mathematics learning outcomes are low. The same thing is also found for the impact of learning independence on students' achievement in mathematics. One of the factors that influenced this finding was the lack of control from the researcher when students filled out questionnaires and took tests because all data collection processes were carried out online. [ABSTRACT FROM AUTHOR]

Chitosan was synthesized from chitin and applied to remove dye contaminants. The dyes used in this study were methyl orange and malachite green. The dye adsorption experiment was carried out in a batch system by studying the effect of pH, contact time and dye strength. The concentration of the dye was measured with a UV-Visible spectrophotometer. Chitosan was able to reduce levels of methyl orange dye by 48.36% after 120 minutes in a pH 3 solution. Chitosan was also able to reduce malachite green dye levels by 76.04% after 100 minutes in a pH 5 solution. The removal of MO and MG contaminants in wastewater with chitosan-based adsorbents is very promising to be widely used as an adsorbent for dye processing. [ABSTRACT FROM AUTHOR]

This study aimed to develop students' critical thinking skills through the environment-based STEAM project in chemistry learning. The study consists of thirty-two students in their 10th grade who used the learning steps of the STEAM project. The environmental-based STEAM project was implemented in the molecular shapes subject through project-based learning. The research employed the qualitative approach to explore the environmental-based STEAM project in chemistry learning and students' critical thinking skills development. The data were collected through classroom observations, interviews, reflective journals, and chemistry concept tests. Students designed an innovation project with the integration of STEAM-based on the environment in molecular shape from environment-friendly materials. The results of the study were analyzed based on the pattern themes, which were found in some multiple data sources. It shows students develop their critical thinking skills with conceptual understanding, ideas connection, and assumption, then care for environmental problems. The study has challenges on integrate environmental-based STEAM in chemistry learning within empowering the students, time resources, and supply the contextual learning to raise the students' environmental awareness in daily lives. [ABSTRACT FROM AUTHOR]

This study investigated the effects of Science, Technology, Engineering, Art, and Mathematics (STEAM) learning to student's achievement in chemistry learning of molecular models topic. The quantitative method of true experimental design was implemented in this study. The random sampling required 80 students in two classes with STEAM learning and the other class with the inquiry. Student's achievements were obtained after the learning process using the essay test. The essay test was consist of seven structured questions that valid and reliable. The findings showed that there were no significant differences in the post-test score between STEAM and inquiry classes. The average score of the STEAM post-test was 44.28 while the inquiry class is 43.65. Statistical test results with t-test also show no difference between STEAM and inquiry classes. Both STEAM learning and inquiry give the same result of students' achievement on the molecular models subject. [ABSTRACT FROM AUTHOR]

The concept of 21st-century education in the era of the industrial revolution 4.0 demands optimal digitalization and computerization innovation. The utilization of technology makes the learning process take place continuously without space and time limits. This study aims to produce electronic-modules (e-modules) as instructional materials for protein structure and function using the Flip PDF Professional application. The method that used refers to the research and development of the Borg and Gall model with a questionnaire research instrument. The research and the development procedures are preliminary study, research planning, initial product development, small scale field test, revision of small scale field test results, large scale field test, and revision of large field test results The electronic module consists of an introduction and discussion of the material (based on the learning design of the Biomolecular Protein Structure and Function course in Chemistry Education undergraduate courses). Besides, the e-module is equipped with videos, images, animations, links to various main sources, and formative tests on each protein structure and function material. Product validation is done based on the material, language, and media experts using standard instruments with a Likert scale. The results of the three experts' validation of the developed e-modules showed good great interpretations. Based on the results of the validation, it can be concluded that the electronic module structure and function of proteins are ready to use as learning media. [ABSTRACT FROM AUTHOR]

A new S2 and S3 sound detection by using the heart rate signal taken from dorsalis pedis artery as a reference is presented in this paper. This approach aims to evaluate the accuracy of the S1 and S2 sounds detection by using dorsalis pedis pulse measurement as a reference. The dorsalis pedis pulse was measured by using MAX 30100 sensor controlled by a microcontroller. Meanwhile, the heart sounds were captured by using the ECG device. The measurement was taken for 5 minutes for a total of ten male and ten female subjects, with the age of 20 years old. This experiment has been conducted several times, and the average was calculated and compared to the existing solution. This proposed approach gives a small error compared to the standard S1 and S2 detection, leading it to be an acceptable and promising solution of a detection method. [ABSTRACT FROM AUTHOR]

The wearable devices are gaining its popularity in recent years. This paper presents the performances of our smart shoes as a wearable biomedical device in capturing the heartbeat signal from dorsalis pedis. Generally, the heartbeat measured from an artery was located on the chest, hand, fingertip, and ear or neck. Even though the pulse from dorsalis pedis has a smaller amplitude compared to the other artery location, the integrated sensor on our smart shoes can capture the signal with high precision. The experiment was conducted several times to three groups of healthy participants; they were kid, mature, and elder. The results show that the smart shoe sensor could measure the dorsalis pedis pulse and has a maximum error rate of 11.76% compared to the digital tensimeter. Unlike the standard measurement and other commercial devices, our device gives a small gap in RMS error, which is acceptable for clinical needs. [ABSTRACT FROM AUTHOR]

This study aims to i) synthesize silver nanoparticle-graphene oxide (Nano-Graver) mixture via liquid sonication exfoliation method using graphite from 2B pencil, ii) characterize the Nano-Graver solution based on UV-Vis, FTIR, XRD, and SEM, and iii) determine the Nano-Graver solution inhibition zone diameter against Staphylococcus aureus (S. aureus) bacteria. This is an experimental research with steps given as follows: i) synthesizing graphene oxide (GO) via the liquid sonication exfoliation (LSE) method, ii) synthesizing silver nanoparticles (AgNPs) chemically from AgNO3, iii) mixing the GO and AgNP solutions to become Nano-Graver, iv) characterizing the Nano-Graver solutions, and v) determining the Nano-Graver solution inhibition zone diameter against S. aureus bacteria via nutrient agar (NA) and blood agar (BA) media. The Nano-Graver solution is successfully synthesized having a dark-yellowish color, compared to a yellowish color solution of the AgNP and a clear solution of GO. The UV-Vis test of the Nano-Graver solution shows two absorbance peaks at wavelengths of 230 nm and 435 nm indicating the existence of GO and AgNP materials, respectively. The FTIR result shows OH and C = C groups, which means GO material occurs in the Nano-Graver solution. The XRD test shows that the Nano-Graver material has a semi-crystalline or amorphous structure. The SEM test for the Nano-Graver solution shows GO in coral-like material decorated by small spheres of AgNPs. The inhibition zone test of S. aureus bacteria produces the largest inhibition zone diameters in NA and BA media of 1.731 cm and 1.043 cm, respectively, for Nano-Graver concentration of 5 mM. [ABSTRACT FROM AUTHOR]

Dynamic assessment (DA) was developed from Vygotsky’s sociocultural theory (SCT) on cognitive development through optimizing students’ potentials and ways of thinking. In several non-scientific studies, DA has shown positive results on various student performances, such as writing skills, critical reading, and listening comprehension. This review was aimed to find out the form of dynamic assessment instruments which oriented to improve students’ cognitive aspects. The PRISMA was used as the research method. 275 articles were collected from the online databases such as Science direct, Eric and SAGE using the keywords “dynamic assessment” and “cognitive.” The articles filtered by the type of article (research articles), titles, abstracts, and keywords. 41 articles declared as relevant with the review purposes. The articles were reviewed by the reviewer team. 11 articles met the criteria for further analysis. The results indicated the diversity of DA instruments for improving students’ cognitive aspects. The types of DA were: multiple choices test (28%), essays test (27%), short answers (9%), physical tests (9%), oral text recalling (9%), Cognitive Modifiability Battery (CMB) (9%), and vocabulary puzzle tests (9%). Various students’ cognitive aspects can be measured using DA, such as the math problem-solving difficulty, analogical reasoning, conceptual knowledge, writing skills, reading and listening comprehension, and cognitive modifiability. The DA was applied by giving feedback (implicit and explicit instructions) in the form of text, oral, or visual aimed to improve the cognitive aspects of students. [ABSTRACT FROM AUTHOR]

Preliminary studies conducted with 45 domestic tourists from outside the city showed that 26 tourists stated they did not intend to revisit Semarang for travel in the future. Travelers who did not intend to visit the city of Semarang in the coming future gave reasons including that they were not satisfied with the existing tourism in the city of Semarang. Satisfaction can affect the tourists' intention to revisit, so if travelers are not satisfied it can lead to reluctance of travelers to come back to the city of Semarang in the future. This study aimed to determine the factors that influence the intention to revisit of tourists visiting Semarang. Variables used to follow the conceptual model were perceived quality, perceived value, satisfaction, and intention to revisit. Respondents selected as samples were 100 tourists who came from outside the city of Semarang who visited within the last two years. The results showed that the perceived quality variable indirectly affected the satisfaction and intention to revisit, but the perceived quality affected satisfaction and intention to revisit through perceived value rating. The variable perceived value had a significant positive effect on satisfaction and intention to revisit. The satisfaction variable had a significant positive effect on intention to revisit. [ABSTRACT FROM AUTHOR]

Nosocomial infections in the hospital cause height level of morbidity and mortality. WHO research referring to nosocomial infections is approximately 8.7% of 55 hospitals from 14 countries in Europe, Arabian, and Asia. Staphylococcus aureus constitutes bacteria that cause nosocomial infections. Objectives of the research are to know how the step, characteristic, and activity of antibacterial for S.aureus from nanoparticle silver-chitosan, and the combination of both materials. The principle of nanosilver particle has antibacterial activity, was proved that silver ions are able to make strong inhibitions on bacteria cell wall. Silver ions will damage and penetrate cell wall bacteria then alternating of DNA bacteria. This condition makes fatality for bacteria. Chitosan was found by chitin deacetylation polyatomic with positive content and pH less than 6,5. Cationic of chitosan can make interaction with the cell wall of bacteria. Material combinations will make interactions and cause the damages on bacteria cell walls and can drag off the growing of bacteria cause of nosocomial infections. The result of the research indicated that silver nanoparticles with spectrums UV-Vis characterization, maximum absorption shows at wavelength 419 nm. The combination of silver nanoparticles and nanochitosan can drag the growth of bacteria S. aureus. The even more silver nanoparticle is working better than nano chitosan as antibacterial. As the conclusion, the application of Silver-Chitosan nanoparticles is effective to drag the growth of bacteria 0.62 cm in nutrient agar or medium of S. aureus that causes nosocomial infections. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine design of mathematical models of teaching materials to improve students' mathematical connection ability and mathematical disposition in middle school through experimental studies. The design in this study was quasi-experimental with non-equivalent control group type. This study consisted of two phases, the first phase was identify students' learning obstacle on square and rectangle concepts to obtain the appropriate design of teaching materials, beside that there were internalization of the values or characters expected to appear on students through the teaching materials. Second phase was experiments on the effectiveness and efficiency of mathematical models of teaching materials to improve students' mathematical connection ability and mathematical disposition. The result of this study are 1) Students' learning obstacle that have identified was categorized as an epistemological obstacle. 2) The improvement of students' mathematical connection ability and mathematical disposition who used mathematical teaching materials is better than the students who used conventional learning. [ABSTRACT FROM AUTHOR]

Chiral Smectic Liquid Crystal (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate has been synthesized using method of steglich esterification at room temperature. The mesomorphic behavior of chiral smectic at 55°C that showed schlieren texture in POM analysis. Fixation of structure chiral smectic liquid crystal by means of photopolymerization of monomer (S)-(+)-4-(2-methyl-1-butyloyloxy)phenyl 4-[1-(propenoyloxy) butiloxy] benzoate under UV irradiation which called UV curing techniques. The curing process using UV 3 lamps 100 volt at 60°C for an hour. The product of photopolymerization could be seen by analysis of FTIR spectra both monomer and polymer. FTIR spectra of monomer, two peaks for ester carbonyl and C-C double bond groups appeared at 1729.09 cm-1and 3123.46 cm-1. After UV curing process, peak for the carbonyl group at 1729.09 cm-1 decreased and a new peak at 1160.21 cm-1appeared due to the carbonyl group attached to a C-C bond group and then peak at 3123.46 cm-1 for C-C double bond group was disappeared. [ABSTRACT FROM AUTHOR]