High band gap 2-6 and 3-5 tunneling junctions for silicon multijunction solar cells

A multijunction silicon solar cell of high efficiency is provided by providing a tunnel junction between the solar cell junctions to connect them in series. The tunnel junction is comprised of p+ and n+ layers of high band gap 3-5 or 2-6 semiconductor materials that match the lattice structure of silicon, such as GaP (band gap 2.24 eV) or ZnS (band gap 3.6 eV). Each of which has a perfect lattice match with silicon to avoid defects normally associated with lattice mismatch

Advanced Czochralski silicon growth technology for photovoltaic modules

Several economic analyses had indicated that large-diameter, multiple ingot growth using a single crucible with melt replenishment would be required for Cz growth to be economically viable. Based on the results of these analyses, two liquid and two solid feed melt replenishment approaches were initiated. The sequential solid feed melt replenishment approach, which demonstrated elements of technical feasibility is described in detail in this paper. Growth results of multiple ingots (10-cm-diameter, totaling 100 kg; and 15-cm-diameter, totaling 150 kg weight per crucible) are presented. Solar cells were fabricated and analyzed to evaluate the effects of structure and chemical purities as a result of multiple growth. The results indicate that, with semiconductor-grade silicon, feedstock impurity build-up does not seem to degrade cell performance. For polycrystalline cells, the average efficiencies are 15 to 25% lower than those of single crystalline cells. Concerns regarding single crystal yields, crucible quality and growth speed are indicated, and present status and future research thrusts are also discussed

Sejarah Sosial Arab-islam Pada Abad VIII Dan IX M (Studi Tentang Pranata Sosial Era Abbasiah)

The history of Islamization in the archipelago, especially that happened since the 16th century has encouraged a writing tradition of religious manuscripts in huge numbers. The manuscripts can definitely be regarded as primary sources for reconstruction a social- intellectual history of Indonesian Islam in the past. One of the most important topics discussed in such sources is that relates to the history of blaming and marginalization of religious doctrine, especially that of Unity of Being (wahdat al-wujūd), or popularly known in Java as Manunggaling Kawula Gusti. This article will examine some Islamic works covering the discourse of controversy between the orthodoxy and heterodoxy that emerged since the mid of 16th and 19th centuries in the Archipelago. The first work that will be consulted is a Sufi treatise entitled at-Tuhfah al-Mursalah ila an-Nabi (the Gift addressed to the spirit of the Prophet) written by an Indian scholar, Fadl Alla>>>h al- Hindi al-Burhanpuri. Furthermore, this article will demonstrate the emergence of ‘derivative\u27 local works of at-Tuhfah, written both in Arabic and local languages. The works contain both opposing and supporting thoughts of the theosophical doctrine discussed in the at- Tuhfah

Power system applications of fiber optics

Power system applications of optical systems, primarily using fiber optics, are reviewed. The first section reviews fibers as components of communication systems. The second section deals with fiber sensors for power systems, reviewing the many ways light sources and fibers can be combined to make measurements. Methods of measuring electric field gradient are discussed. Optical data processing is the subject of the third section, which begins by reviewing some widely different examples and concludes by outlining some potential applications in power systems: fault location in transformers, optical switching for light fired thyristors and fault detection based on the inherent symmetry of most power apparatus. The fourth and final section is concerned with using optical fibers to transmit power to electric equipment in a high voltage situation, potentially replacing expensive high voltage low power transformers. JPL has designed small photodiodes specifically for this purpose, and fabricated and tested several samples. This work is described

Generation, detection and applications of in vitro oxygen gradients

Oxygen homeostasis is critical for the functioning of multicellular organisms. Deficiency of oxygen or hypoxia can lead to several pathological conditions such as ischemia, tumorigenesis and drug resistance. Most studies utilize specialized O2 incubators to generate singular oxygen concentrations that vary significantly from the physiological conditions where hypoxic gradients exist within the tissue e.g. in solid tumors. Current microfluidic technology using polydimethylsiloxane-based (PDMS) devices enables generation of such oxygen concentration gradients, but yield low-to-moderate spatial resolution, involve tedious device assembly and are not feasible for practical research or pharmaceutical screening. We have developed a novel and simplistic approach of reproducibly and rapidly generating stable biomimetic oxygen gradients with high spatial resolution and integrated detection capability. The microfluidic split and recombine strategy utilizing O2-rich and O2-depleted media allows generation of prolonged dissolved oxygen (DO) gradients while an underlying platinum based sensor layer (PtOEPK) allows real-time detection of DO gradients generated. Deposition of an approximately 5-7µm thick three-sided glass coating prevents multi-directional diffusion of ambient oxygen through PDMS maintaining the gradient stability for hours or days. Two variations of the gradient devices have been developed, one offering the ability to generate continuous gradients within a single channel while another containing multiple outlet chambers each maintaining a specific concentration of DO (Figure 1). Please click Additional Files below to see the full abstract

Growth Model of Pine (Pinus merkusii Jungh. Et de Vriese) Stand on Community Forest in Tana Toraja Regency

Growth modeling and yield simulation of forest is a very important aspect in forest management including community forests. Stand growth model is an abstraction of the dynamic nature of a forest stand, including growth, ingrowths, mortality, and other changes in the structure and composition of the stand. In forest management, growth estimation plays an important role in supporting the sustainability of the benefits value of the community forests. The objectives of the research were to find out the stand growth model and the potential of community's pine forest. The study was conducted at the location of the community pine forests in District Mengkendek Tana Toraja Regency. Sample location, as representative of stand age classes that distribute on some villages in Mengkendek District, were selected by purposive sampling.The study results indicate that the most suitable model for upper trees mean height (H) is Weibull Model, for growth diameter and growth volume is Logistic Model  . The stand mean height (h) can be presented as a function of H and Relative Spacing Ratio (Sr) on the basis of function log Sr = 0,197 – 0,653 log H, then the tree volume, can be estimated on the basis of function log V = -1,70 + 0,94logD + 1,50logh, and then the growth function of volume on the basis of function V = 1.008 / 1 + 251.322 exp(-0.373t. Further, the maximum value of stand Annual Increment was 18 m3ha-1year-1, attained at the age of 20 years

Project-based learning based on local wisdom through google classroom to improve process skills in pandemic times

This research aims to improve the science process skills of biology education students during the Covid 19 pandemic. This research was carried out at the Biology Education Study Program, the University of Flores, from May to July 2021. The type of research used is experimental research with observation and product assessment. The process skills, performance, and product assessment data are then analyzed using a simple statistical formula and then converted into value categories and interpreted based on the criteria. The quality of improving science process skills is measured using the N-gain formula and categorized based on the rubric of improvement interpretation. The results show that project-based learning based on local wisdom through google classroom is proven to train science process skills 85% to 89% in the good category with the quality test for improving science process skills in the high category. In addition, the results of measuring project performance skills that integrate the potential of local wisdom in the project get a score of 85% to 90% in the good and very good categories. Product ratings get an average score of 87% for product appearance and 83% for product quality, and both are in a good category. So, it can be concluded that the project-based learning (PjBl) model based on local wisdom through the google classroom media can train and improve several science process skills and performance can also increase the competence of prospective biology teacher students through real work of scientific product creativity

Kajian Ekonomi Wilayah Dan Kelembagaan USAha Peternakan Ayam Ras Petelur Di Kabupaten Tasikmalaya (the Spatial and Institutional Economic Analysis of Layer Broiler Farming in the District of Tasikmalaya)

The theme of this study is the spatial economic of layer-broiler production in Tasikmalaya district. The study was accomplished in eight months, from April to November 2008. Its purpose is twofold; first, to identify the spatial economic of layer-broiler production; and second, to describe the properties of its institutional performance. The data was collected through surveys, and subsequently analyzed by means of localization indices, specialization indices, LQ and the structure – conduct – performance (SCP) approach. The analysis revealed that layerbroiler farming on the area yet have not enough contributed to the regional economic of Tasikmalaya. In addition, the aspect of availability and accessibility to feed resources, and the aspect of marketing have been identified as a critical point for further development of layer-broiler industry in the future. Keyword : spatial economic, localization, specialization, LQ, SCP

KKNM-Bimbingan Belajar Siswa SD Kelas 1 selama Masa Pandemi Covid 19 di Desa Kenere Kecamatan Solor Selatan Kabupaten Flores Timur

Kenere Village is one of the villages in the South Solor sub-district, East Flores district. In this COVID-19 pandemic situation, community activities are limited so that teaching and learning activities for students in schools are also limited resulting in many students being careless in learning. Therefore, with the guidance carried out at school and following the provisions that students who come to school at least 4-5 people besides that guidance is also carried out from home or BDR with this guidance activity students are guided to train and guide students who are slow in learning to better study hard to get good results. Guidance activities are very influential on the learning process of elementary school children in grade 1, with this guidance many students experience changes before and after the activity. Students who are slow to learn can be overcome with tutoring and will foster good learning achievement. In this tutoring, the media or tools used are notebooks, pencils/pens, package books, letter cards and alphabetic calendars