IPTEK Journal of Proceedings Series
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Cellulase, Pectinase, and Xylanase Production by Listeria sp. ISH 16 using Coffee Pulp Waste Medium
Full text linkIn this study, microbial utilization of coffee pulp waste to produce three carbohydrases (cellulase, pectinase, and xylanase) has been investigated. An isolate Listeria sp. ISH-16 which grown in liquid medium containing 0.5% coffee pulp alkali extract can grow well with density of reach 107 x 58.5 cell/mL. Further, the culture can optimum produced of pectinase after 72 hours incubation at 37oC, but for cellulase and xylanase longer 84 hours incubation needed. The harvested of crude pectinase, cellulase and xylanase had activity 0.15, 0.23, and 0.61 unit/ ml after dialysis, respectively. All enzymes stable at a range of pH 4-5.5, but they work optimum at different pH. Of each enzyme pectinase, cellulase, and xylanase work optimum at pH 5, 4.5, and 5.5. based on these results, it may be adopted as a strategy to produce enzymes with low cost so that further investigation such as large scale and purification enzyme is needed
Goal Programming Model for Optimizing The Management of Brackish Water Milkfish Ponds in Gresik
Full text linkNational fish consumption is increasing every year, both sea fish and fish farming. That is because the appeal and invitation of the government to consume fresh fish (white meat) which contains lots of vitamins and protein. Milkfish is one of the most consumed fish species because it is easy to get and the price is relatively cheap. One of the biggest milkfish producers in East Java is located in Gresik Regency. The fulfillment of milkfish consumption needs depends on its productivity. Milkfish productivity depends on the area of the pond. The greater the land area, the more milk fish can be produced. However, milkfish farming is often constrained by the size of ponds, so the amount of milkfish harvest is also limited. In this study, the goal programming method is used to obtain several objectives, namely maximizing profits, minimizing capital, minimizing production costs and inventory costs, taking into account the changing demands in each harvest period, population density, milkfish survival rate and growth rate. The profit from selling the harvest can be optimized by selling some fish (on demand) and re-raising the remaining milk fish from the harvest (inventory) for resale in the next harvest period. Although production costs and inventory costs increase with more food, these benefits will be maximized compared to selling the entire harvest during that period. Because the greater the weight of milk fish, the higher the selling price. So the benefits will be far more leverage
Controlled Morphology of Silica Particle by Spray Drying Method
Full text linkThe controlled morphology of mesoporous silica particle with colloidal silica as precursor solution was investigated using spray drying method. The colloidal silica solution was made from sodium silicate (waterglass) using sol-gel method. The operating condition of spray dring such as precursor solution volumetric rate and hot air flowrate was varied to study the effect of the silica particle’s morphology. Two-fluid nozzle was used as atomizer with volumetric rate ranged from 1.6 mL/min to 5 mL/min, and hot air heated from tubular furnace with flowrate ranged from 210 L/min to 414 L/min, both resulting doughnut-like shape with more doughnut fraction with increased volumetric rate. With the increase of volumetric rate from 1.6 mL/min to 5 mL/min, the surface area and total pore volume are tend to decrease (168.234 to 131.001 m2/g and 0.1652 to 0.1251 cc/g respectively). Meanwhile, for increasing hot air flowrate from 210 L/min to 414 L/min, the surface area are tend to increase (135.353 to 168.234 m2/g) but total pore volume tend to decrease (0.1921 to 0.1652 cc/g)
Vibration Spectroscopy Potential for Beef and Pork Extending Tradition: Design Criteria for Developing of Authentic Banjar Settlements on River Banks in Banjarmasin
Full text linkBanjarmasin city has the character of settlements along the river that reflects the concept of the authentic Banjar settlements on river banks as a product of Nusantara architecture’s. However, the existence of these settlements began to lose their existence due to changes in life orientation from river culture to landed culture. To restore the existence of these settlements, the government of Banjarmasin city plans to develop these settlements into tourist villages with Banjar culture. This encourages optimization of existing potential by improving the quality of settlements that pay attention to various aspects in the context of the location being developed, such as environmental damage, water quality, and applicable regulations. Although there are many design criteria related to riverbank settlements in Banjarmasin, there are some aspects that have been neglected such as the cultural aspects of urang Banjar which are related to the river and Islam. This has an impact on the quality of settlements that reduce the level of kinship in the Banjar community. By using a force-based framework, the design criteria will be formulated by applying a strategy of extending tradition. The design criteria produced, cover various design aspects that are closely related to activities, order, form, building construction, supporting elements, and circulation patterns to improve the quality of the settlement, so that it can develop into a self-sustaining area with food security, energy sources, and the conservation area of Banjar culture
Aceh Cultural Elements in the Settlement Context
Full text linkIndonesia consists of various diverse tribes and cultures. Culture is the result of people's thoughts and behavior. Culture can also act as the identity of a tribe that has its characteristics. The difference in characteristics is interesting to study, one of which is the culture of Aceh in Indonesia. Aceh is rich in cultural values and customs because of its historical background. Influences from various backgrounds eventually shaped the characteristics of Acehnese. The culture of Aceh has been discussed in several studies, but no one has focused on the context of settlement. Therefore, this study was conducted to analyze aspects of Aceh's culture in a settlement. Cultural aspects can be analyzed based on world views, values, manifestations, activity systems, and social expressions. This study is a literature review, which uses secondary data to answer the research objectives. Secondary data were obtained from literature related to research topics, such as books, journals, regulations, etc. Furthermore, the data collected will be analyzed and concluded using descriptive analysis. The study results explain that every aspect of Aceh's culture refers to Islamic rules, where the balance between customary law and religious law is important for Acehnese lives
Land Acquisition Problems Project for Electrical Infrastructure Development
Full text linkThe land is a critical resource for infrastructure development. However, land acquisition was still as the biggest problem in realizing infrastructure development in Indonesia. Electricity project is one of the infrastructure projects strategic and needs to be realizing in a short period. Effort at investigating the factors causing a problem in land acquisition for electricity infrastructure projects through an empirical method in Indonesia received scant attention. Therefore, the purpose of this study is to identify and critically assess the factors causing land acquisition problem for electricity infrastructure development using an empirical approach. The study adopted literature review and questionnaire survey. Literature review was using to identify the factors causing in land acquisition problem, which was using to design the questionnaire survey culminating in data analysis. In order to capture a broad perception, the questionnaires were administered to three different primary stakeholder groups comprised consultants, project owner and government. Data collected were analysed using mean score. The study revealed the mean score ranking of 24 identified factors causing in land acquisition problem for electrical infrastructure development. Five highest problems in land acquisition projects are (1) A project has not integrated with City Plan; (2) The part of land that is not acquired cannot be utilized by the owner; (3) Inventory data is not accurate; (4) Poor stakeholders coordination; (5) Differences interpretation of land acquisition regulations
The Impact of Folding Shutter on the Daylighting Performance in Tropical Climate
Full text linkUtilization of abundant sunlight in tropical climates as daylighting can help to save energy consumption in the flats building. Based on daylight conditions in tropics, there is a need for a dynamic shading to be applied in façade which can be transformed to respond to the environmental change. Folding shutter is a dynamic shading device which can be operated by using folding and rotation motion. This paper aims to discuss the impact of folding shutter on the daylight performance in the context of flats buildings in tropical climates. Simulation using Radiance was conducted to test the sub-variables of folding shutter, including the folding configurations and shutter’s rotation angles on different conditions in tropics. The results showed that folding configurations results in high increase of daylight intensity and should be applied moderately. Meanwhile the shutter’s slats can help to diffuse and reflecting incoming light to the deepest areas of room. A closed configuration with shutter’s angle of 0° and 45° performed the best to face the inconsistent cloud movement in partly cloudy sky. The integration of folding shutter and 60 cm overhang produced the most stable performance which can meet the visual comfort standard in the longest period in tropics
Vibration Spectroscopy Potential for Beef and Pork Determination
Full text linkMeat is one of the most foodstuff consumed. The increasing consumption of meat had led some traders to falsify the identity of meat for gaining profit. The meat adulteration case that often occurs is substituting the beef with pork. This adulteration case is very detrimental to consumers, therefore a method to identify the type of meat sold is very necessary. The vibration spectroscopy method, Fourier Transform Infra Red (FTIR), had been developed to analyze the type of beef and pork. The FTIR measurement was carried out with cut raw meat samples without further preparation. The Data obtained from the measurement are infra-red spectrum from beef and pork from 4000-500 cm-1 wavenumber and then the data was analyzed with Principle Component Analysis (PCA) statiscticall method. Projection result with PCA obtained data reduction that can represent all data generated from measurements shown through the Principle Component 1 and Principle Component 2 regions. Based on those projection, beef and pork profile area can be classified properly
Effects of Pivot Windows and Wing Walls on Single Sided Natural Ventilation in Rumah Susun (Walk Up Flat)
Full text linkRumah susun (walk up flat) are one of the buildings that rely on natural ventilation. However, the application of natural ventilation in rumah susun (walk up flat) in urban areas is influenced by tropical climate problems such as high temperatures and low wind speeds. The design of the openings in the facade has not been able to distribute air into rooms properly. In addition, the layout design makes single-sided natural ventilation the only strategy possible for double loaded corridor type flat. This study aimed to determine the effect of a combination of pivot window designs and wing walls in directing and distribute air into room. The study was conducted in two stages, that was field measurements and experimental with Computational Fluids Dynamics simulations. Simulations were conducted on a combination designs of wing walls and pivot window with 45o and 90o opening angles to determine their effects on the distribution and indoor air velocity. The combination design of wing walls and pivot window created a pressure difference so that it could increase indoor air velocity under both oblique and parallel to the opening. In the direction of the wind that was not oriented to the openings, the combination of wing walls and vertical pivot windows with 90o opening angles increased indoor air velocity up to five times in the corner room. While the 45o opening angle increased the indoor air velocity up to seven times than base case condition in a middle room
The Effects of Mobile Payment Dimensions toward Continuance Intention in Surabaya
Full text linkThe 4.0 industrial revolution allows people to make payments using mobile devices which is called mobile payment. Mobile payment users in Indonesia have enlarged a significant improvement in the last few years. However, the use of mobile payment in Indonesia has not dominated yet. Most of the payments that they use are ATM Transfers, debit cards, and internet banking. These indicate the lack of continuance intention in using a mobile payment. The aim of this study is to examine the effects of mobile payments dimension (mobility, customization, security, reputation), service quality toward continuance intention through trust, and also the effects of trust toward continuance intention through perceived risk. The data used in this study are obtained through a research questionnaire. Respondents in this study were 170 Go-Pay and OVO users domiciled in Surabaya who made transactions with Go-Pay and OVO at least twice in the last few months. The sampling method of this study was non-probability sampling. This study uses a quantitative approach with the Structural Equation Modeling (SEM) method for statistical test. SEM analysis was carried out using the Analysis of Moment Structures (AMOS). The results of this study indicate that mobility and security have a significant positive effect on trust. On the other hand customization, reputation, and service quality do not affect trust. Trust has a significant positive effect on continuance intention and perceived risk. Meanwhile, the perceived risk made a significant negative effect on continuance intention