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Gypsum board is one of the advanced products of gypsum material with a mixture of fiber/fiber or other materials. Gypsum board has a weakness in its physical properties that easily absorb water. Therefore, there is a need for innovation in the manufacture of gypsum boards that will produce even better quality. The manufacture of gypsum board can utilize waste materials such as coconut shells and rice husks and latex as adhesives. The mixture of gypsum board materials including: gypsum, coconut shell, and rice husk used was 70%, 15%, 15% with latex variation 10%, 12%, 14%, 16%, 18% with FAS 0.5 and drying for 28 days. The parameters of the physical properties test include: density and thickness expansion, as well as microstructural testing to determine the morphology of the gypsum board sample. Analysis of the physical properties of gypsum board obtained optimal results, namely in sample A with a variation of 10% latex composition, the density value was 1.35 g/cm3, and the thickness expansion was 5.03% which met the SNI Standard 01-4449-2006. While the microstructure produces morphological images that show inhomogeneous distribution, particle agglomeration forms, and impurities

Ceiling evelopment by utilizing waste corn cobs, coconut coir with gypsum flour an the adition of latex adhesive. Variations in the composition of the mixture of corn cobs, coconut coir, gypsum flour with latex adhesive include sample A (0:0:100:15), sample B (3:3:94:15), sample C (6:6:88:15), sample D (9:9:82:15), sample E (12:12:76:15), and sample F (15:15:70:15) with emphasis using a hot press and drying for 28 days. The test parameters include flexural strength and fracture strength. The test results show that sample B in the composition (3:3:94:15) is the optimal result. In this composition, the resulting ceiling board has the characteristics of a flexural strength of 3966,39 kgf/cm2 and a fracture strength of 1088,6 kgf/cm2.Keyword : Lateks , Ceiling Board, Coconut Coir, Corn Cob

This test was carried out to reduce waste in coconut empty fruit bunches and to determine the characteristics and microstructure of the particle board surface. The samples used consisted of bamboo powder and oil palm empty fruit bunches with gambier adhesive and urea formaldehyde with variations including: 10%:75%:15%:11%; 20%:65%:15%:11%, 30%:55%:15%:11%, 40%:45%:10%:11%. The particleboard was printed and pressurized using a hot press of 16kg/cm2 for 15 minutes at a temperature of 120 oC, with a drying time of 14 days. The test parameters include: density, moisture content, thickness expansion, and microstructural analysis using SEM (Scanning Electron Microscopy) which refers to SNI 03-2105-2006. The characterization of particleboard produced in the density test is 0.66-0.74 g/cm3, the water content value is 2.4-6.9%, the thickness expansion value is 7.2-12%. Based on the percentage value of the density of the resulting particleboard is a medium density particleboard.

It has been done making bricks with the addition of cotton.Variations in the mixture of cement, sand and cotton are sample A (30%:70% :0%), sample B (30%:69,5%:0,5%), sample C (30%:69%:1%), sample D (30%:68,5%:1,5%), Water Cement Factor of 0,5 and dry time one day. Characteristic of the tests carried out include: compressive strength and fracture strength.Analysis of the mechanical properties of the bricks produced in sample A with a compressive strength value = 28.81 kg/cm2 and fracture strength value = 23.11kg/cm2, sample B with acompressive strength value = 26.85 kg/cm2 and fracture strength value = 22.32 kg/cm2, sample C with a compressive strength value = 25.10 kg/cm2 and fracture strength value = 15.09 kg/cm2, sample D with a compressive strength of 17.14 kg/ cm2 and a fracture strength value 15.51kg/cm2. The bricks produced namely in sample B.Keywords :Bricks, Cotton, and Cement

Biobattery research has been carried out using cassava leaves (Manihot Utilissima) as a substitute for carbon in some 1.5 volt batteries. And tested the voltage with the results of sample A: 1.53 volts; B: 1.54 volts; C: 1.55 volts; and D: 1.58 volts. Then the electric current was also tested with the values obtained in sample A: 0.08 mA; B: 0.10 mA; C: 0.13 mA; and D: 0.19 mA. If the carbon mass in the biobattery gets higher, the value of the voltage and electric current test results changes with the higher in each sample. By performing the performance on the cassava leaf biobattery, it is able to turn on a 2.5 watt LED lamp with 3 batteries. Keywords: Current, cassava leaves, and voltage

Abstract. This study aims to determine the effect of optimal physical properties and microstructure on particleboard samples. The percentage variations of cocoa pod peel powder mixture, styrofoam with epoxy resin adhesive were sample A (69:0:30), sample B (68:2:30), sample C (67:3:30), and sample D (66:4:30). 6:30). The materials were compressed were a hot press and a conditioning time of 14 days. sThe most optimum particleboard sample was found in sample B with values of density, moisture content, and thickness expansion, respectively 0,80 g/cm2, 7,74%, and 9,32%, and met the standards of SNI 03-2105- 2006. The surface shape of the particle board morphology in sample B shows the composition of the material with the adhesive binding optimally so that there are very few empty spaces or cavities. Keywords: cocoa pod husk powder, styrofoam, particle board, epoxy resin.

A pulp-based ceiling board has been made. Variations in the composition of mixing cement and pulp used include: 70%: 30%, 60%: 40%, and 50%: 50% and Variations in the composition of mixing cement, sand and pulp used include: 50%:20%:30%, 40%:20%:40%, 30%:20%:50% with FAS 0,4 and the printing and pressing time is 24 hours. The parameters of the test include: water absorption and density. Analysis of the ceiling board physical produced in sample A with a composition of 70%: 30% has a water absorption value = 19% and density = 1.58%, in sample B with a composition of 6%: 40% has a water absorption value = 26 , 8% and density = 1.53%, in sample C with a composition of 50%: 50% has a water absorption value = 26.05% and density = 1.45%, in sample D with a composition of 50%:20%:30% has a water absorption value = 24,3% and density = 1.67%, in sample E with a composition of 40%:20%:40% has a water absorption value = 20,9% and density = 1.45%, in sample F with a composition of 30%:20%:50% has a water absorption value = 14,8 % and density = 1.34%.

The particle board was made based on mixing durian skin and sugar cane bagasse with urea formaldehyde adhesive. The variations the composition of mixing durian skin, sugar cane bagasse with urea formaldehyde adhesive used among other: 35%:35%:30%, 30%:30%:40%, and 25%:25%:50% and printing time and pressing for 24 hours. The parameters of the testing include: Modulus of Rupture (MOR) dan Modulus of Elasticity (MOE) . Analysis of the mechanical properties of the particle board produced at the composition of 35%:35%:30% which has a value MOR = 446,17 kgf/cm 2 and MOE = 160,9 kgf/cm 2 , at the composition of 30%:30%:40%, has a value MOR = 1369,57 kgf/cm 2 dan MOE = 3903,3 kgf/cm 2 , at the composition of 25%:25%:50%, has a value MOR = 1463,07 kgf/cm 2 , dan MOE = 3342,1 kgf/cm 2 which matches SNI 03-2105-2006 criteria type 8 is not required.

Transmission of infectious diseases in epidemiological models is usually based on the assumption that populations in random mixing. However, in reality this assumption is not fulfilled, because each individual has a limited set of contacts that they can pass through infection; the ensemble of all such contacts forms a complex network. Knowledge of network structure allows a model to calculate the dynamics of an epidemic at a population scale from individual level infection behavior. This paper discusses mathematical models to illustrate the epidemic pattern of transmission of infectious diseases in dynamic networks based on compartment systems.

The making of lightweight concrete for lightweight construction materials has been conducted with raw materials based on organic waste from households. The purpose of this study was to utilize household organic waste as aggregate for the manufacture of lightweight concrete. The materials used consist of organic waste, sand, cement, and latex resin with the variation of organic waste composition are 0, 25, 50, 75, and 100% by volume and the addition of latex resin are 10, 12, and 14% by volume. Test parameters performed include density, water absorption, shrinkage, compressive strength, tensile strength, and flexural strength. The result showed that the optimal composition of produced concrete are 25% by volume of waste and 12% by volume of latex resin with the density = 1.46 g/cm3, water absorption = 26.70%, shrinkage = 0.143%, compressive strength = 7.10 MPa, tensile strength = 2.10 MPa, and flexural strength = 2.67 MPa. Keywords : Latex, lightweight concrete, and organic waste.

Study on the effect of comparison and improvement of water quality using electrocoagulation and carbon filter methods has been conducted . This study aims to find out a safe method to be an alternative in producing clean water up to drinking water that can be used to meet daily needs in accordance with clean water and drinking water standards. The parameters tested include physical parameters (temperature, TDS, turbidity, color, odor, and taste), chemical parameters (pH, iron (Fe), and aluminum (Al)), and microbiological parameters (E. coli and Coliform Bacteria). The test results show that water purification using activated carbon is much better than water test result by electrocoagulation method. This is reflected in physical and chemical parameters that have met the clean water standard (Permenkes RI No. 416/1990) and drinking water standard (No. 492/MENKES/PER/IV/2010). As for microbiological parameters are still not meet the clean and drinking water standards. Keywords : Activated carbon, electrocoagulation , and filter s.