PEMETAAN POTENSI PENGEMBANGAN PERIKANAN BUDIDAYA DI WILAYAH PESISIR KOTA PROBOLINGGO

Kota Probolinggo memiliki potensi tinggi pada berbagai kegiatan perikanan di pesisir. Hal ini karena didukung oleh perbatasan utara daerah yang berupa laut yaitu Selat Madura. Adanya sumber daya alam yang seperti itu, usaha budidaya perikanan kini semakin berkembang. Namun, pengaturan dan tata guna lahan belum tertata dengan baik. Oleh karena itu, perlu dilakukan inventarisasi kondisi eksisting kegiatan perikanan budidaya yang ada di kota Probolinggo melalui kegiatan pemetaan potensi pengembangan perikanan budidaya. Dimana merupakan salah satu kajian untuk melakukan inventarisasi awal terhadap potensi perikanan budidaya ini. Pemetaan dilakukan dengan memanfaatkan Sistem Informasi Geografis (SIG). Berdasarkan kajian yang dilakukan, diketahui bahwa komoditi usaha perikanan budidaya yang dapat dilakukan di wilayah Kota Probolinggo adalah ikan bandeng, nila, udang, lele, gurame, dan sidat. Dimana luasan total area potensi budidaya untuk semua kecamatan adalah 279.143 m2. Sedangkan potensi wilayah yang dapat dikembangkan untuk kegiatan perikanan budidaya berdasarkan eksisting usaha budidaya di Kota Probolinggo terdapat 19 titik wilayah pengembangan. Berdasarkan analisis pendugaan sebaran potensi perikanan budidaya, di Kota Probolinggo terdapat 6 titik potensi wilayah yang dapat dikembangan untuk kegiatan perikanan budidaya berdasarkan kedekatan dengan sumber air

Impact properties analysis of rotationally molded polyethylene and polypropylene for a wide range of temperatures

Rotational molding is an established and growing manufacturing method for large, hollow plastic components. In this work the impact properties of rotationally molded Polyethylene (PE) and Polypropylene (PP) were tested at temperature in the range of -40 °C to 30 °C. Dynamic mechanical thermal analysis (DMTA) was performed to analyse the measured impact properties of PP and PE plastics. For PP, a very good relationship was found between peak impact strength and the loss modulus curve obtained in DMTA analysis. A relationship between density, β peak height and peak impact strength was found for PE which is different from previous findings in the literature. It is concluded that further work should focus on developing an understanding of the PE material's microstructure in order to more fully understand its impact properties

Submodular utility optimization in sensor networks for capacity constraints

With the fast development of wireless sensor network (WSN) technologies, WSNs have widely shifted from a specialized platform for a single application to an integrated infrastructure supporting multiple applications. It is hence a critical problem to allocate multiple applications to multiple sensors in order to maximize user utility subject to various resource constraints. The resulting constrained optimization problem is difficult since it is discrete, nonlinear, and not in closed-form. In this report, we develop an efficient optimization algorithm with rigorous approximation bounds for submodular monotonic optimization with multiple knapsack constraints. Based on a variance reduction formulation, we prove several important theoretical properties, including the monotonicity and submodularity of functions and the multiple knapsack structure of constraints. Then, by exploiting these properties, we propose a local search algorithm with fractional relaxation of constraints and prove the approximation bound that is better than any known results. Experimentally, we verify the theoretical properties on a large dataset from the Intel Berkeley Lab. Comparison against other constrained search algorithms show that our algorithm is superior in both solution time and quality, making it a practical choice for WSN design

Fracture properties analysis of rotationally moulded plastics for their application in skin-foam-skin sandwich structure

Rotational moulding is a low pressure, high temperature manufacturing method and is considered to be the best for making large hollow shape plastic parts. Due to its long heating cycle, mould rotation during heating and slow cooling rate, it is completely different from injection or other moulding processes. The mechanical properties of rotationally moulded plastics are totally dependent on unique heating or cooling cycles. With the growing demand for rotationally moulded plastics in load bearing and other applications, a better understanding of their fracture properties is essential. In the rotational moulding process, multilayer plastic products such as skin-foam-skin three layered sandwich structures can be manufactured in a single manufacturing step without any joints. It exhibits relatively high stiffness, strength-to-weight ratios and is used increasingly in various applications such as automotive and marine. During the lifetime of the sandwich material, it may face multiple or repeated impact events. Therefore, the aim of this work is to develop a better understanding of the fracture behaviour of rotationally moulded plastics in order to use them in skin-foam-skin sandwich structure and reduce in-service failures due to impact. Here, rotationally moulded two different commercially available Polyethylene (PE) and Polypropylene (PP) plastics are tested. Microstructural details of the plastics are investigated here. Fracture properties, particularly fracture toughness properties are studied using J-integral elastic-plastic fracture mechanics approach to identify the fracture initiation point. Impact properties are also investigated at a wide range of temperatures. PE materials are found to have better fracture properties. It is observed that with the fracture toughness plastic’s microstructure particularly crystal and amorphous region thickness are related. The understanding from these works is followed by the manufacture of rotationally moulded skin-foam–skin sandwich structure and testing of low velocity impact properties of this structure from 20 J to 100 J energy level with a drop weight impact testing machine. PE is used for both in skin and core layer and sandwich samples are manufactured at four different skin-core thickness combinations. Impact force resistance and bending stiffness are found to be increased with an increase of both skin and core layer thickness. Low velocity repeated impact properties of the rotationally moulded sandwich samples are also investigated from 20 J to 50 J energy level at the end of this project to understand the effect of repeated impact on the sandwich structure. The samples are subjected to single impact event repeatedly up-to penetration at each energy level. Impact energy-impact number curve obtained from repeated impact test provides an equation for prediction of the number of repeated impacts for the penetration of the sandwich samples at each energy level

COVID-19 Prevention: Role of Activated Carbon

Recently, Coronavirus Disease 2019 (COVID-19) has brought the whole world into a pandemic condition, where the number of infected cases and deaths is exponentially high. A number of vaccines are available for this novel virus, but these are in the preliminary stage and are also not available to everyone. As the virus is very contagious, protection and prevention are the best way to survive and get rid of this disease. The virus affects the human body by entering through the nose, mouth, and eyes, so face protection with an appropriate mask is highly advisable. Combined masks made with activated carbon (AC) can effectively adsorb the virus because of its high surface area and broad functional groups. Such combined masks can also control coronavirus transmission by capturing harmful gases and smoke as they help in decreasing the spread of the viru

Composition and diversity of phytoplankton from mangrove estuaries in Sarawak, Malaysia

The composition and diversity of phytoplankton were studied along with physico-chemical parameters of water of two mangrove-dominated estuaries i.e., Kuala Sibuti (KS) and Kuala Nyalau (KN), Sarawak, Malaysia. A total of 46 species of phytoplankton with the mean density of 147000 cells L-1 were recorded from KS estuary i.e., 3 species of Cyanophyceae; 22 species of Bacillariophyceae; 20 species of Dinophyceae and 1 species of Chlorophyceae. The recorded mean density of phytoplankton was 113000 cells L-1 with 33 species from 19 genera from KN estuary, in which 19 species were from Bacillariophyceae; 12 species were from Dinophyceae; 1 species was from Cyanophyceae and 1 species was from Chlorophyceae. In both the estuaries, the species composition was found to be in an order of Diatom>Dinoflagellate>Cyanophyceae>Chlorophyceae. Canonical Correspondence Analysis (CCA) revealed that the abundance of Bacillariophyceae and Dinoflagellates was influenced by salinity and conductivity along with ammonium and phosphate while the abundance of Chlorophyceae was influenced by temperature, TDS, DO and pH in KS. The influence of salinity and conductivity along with PO4 and NH4 on the abundance of Bacillariophyceae, Dinoflagellates and Chlorophyceae were observed in KN