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This study aims to determine the effect of combustion temperature on the microstructure and particle diameter of the average silica ash of cocoa shells, and to determine the effect of combustion temperature on the silica content of cocoa shell ash. The method used is experimental through a quantitative approach. The basic material used is cocoa husk (Theobroma cacao) with combustion temperatures of 450, 550, 650, and 750 oC. The tests used to determine the microstructure and silica content of cocoa husk ash were SEM and XRD after which they were analyzed again using Digimizer Software and X-Powder Software. SEM results based on microstructure indicate the occurrence of agglomeration in the cocoa ash silica sample, and it is known that the particle diameter size of sample A = 1,6916 µm, sample B = 0,7824 µm, sample C = 0,7809 µm, and sample D = 0,7173 µm. Based on the XRD results, it can be seen that the silica contained in sample A = 34,8%, sample B = 49,0%, sample C = 65,0%, and sample D = 70,6%. Based on the SEM results, the best results are in the sample which has the smallest size, namely sample D with a particle diameter of 0,7173 µm and based on XRD results the best results are in sample D with the highest SiO2 content of 70,6%. So that the combustion temperature affects the results of SEM and XRD where the effective temperature in the manufacture of cocoa shell ash silica is 750 oC

Telah dilakukan penelitian Prototipe Smart home dengan arduino ATMega 328 yang dapat mensimulasikan penerapan Smart home yang aktif dengan cara menyambungkan perangkat-perangkat elektronik ke internet dengan mikrokontroler, saat memproses seluruh data berbentuk Input dan Output, dengan sistem kontrol melalui arduino dan didukung dengan sensor MQ-2, flame sensor, Sensor PIR, relay, buzzer, pompa air, sensor PH, Ultarsonik PH, RTM dan kipas. Metode yang diterapkan pada penelitian ini adalah monitoring dan sistem kontrol pengembangan yang membantu pengguna untuk mengetahui dan mendapat informasi mengenai kondisi yang terjadi di rumah, perancangan ini juga dibekali dengan sensor MQ-2 ketika sensor melakukan pendeteksian maka kipas 5 V akan hidup untuk menghisap gas/asap keluar ruangan, sebagai kelanjutan jika terjadinya kebocoran gas maka prototipe ini dibekali juga dengan Flame sensor yang dapat menghidupkan pompa air sebagai penanggulangan kebakaran dengan konsentrasi sensor bekerja pada panjang gelombang kurang dari 450 nm, juga dibekali dengan sensor PIR yang akan menghidupkan alarm jika terdeteksi adanya penyusup di dalam rumah dan di genteng. Dan terakhir Smarthome ini juga di bekali kolam pintar yang diguanakan untuk mempermudah kontroling jika ingin membdidayakan ikan.

Keramik berpori adalah keramik dengan pori-pori dengan distribusi ukuran tertentu dan porositas yang relatif tinggi. Penelitian ini bertujuan untuk mengetahui uji fisis keramik berpori dan mengetahui variasi paling optimum. Peneltian ini menggunakan komposisi clay dan kulit kakao dengan variasi sampel A (75%:25%), B (70%:30%), C (65%:35%), dan D (60%:40%). Parameter pengujian uji fisis keramik berpori yaitu Penyerapan Air dan Porositas. Hasil pengukuran penyerapan sudah memenuhi SNI 8640:2018 Tentang standart mutu bata ringan pasangan dinding. Sedangkan pengukuran porositas sudah sesuai dengan referensi penelitian sebelumnya. Variasi optimum yang didapat yaitu pada sampel D dengan nilai pengukuran penyerapan air keramik berpori sebesar 21,73% dan pengukuran porositas keramik berpori sebesar 13,54%.Kata kunci : Keramik Berpori, Kulit Kakao, clay

Penelitian ini sudah dilakukan bertujuan mengenali bagaimana mutu air sumur gali saat sebelum serta sesudah difilter dengan bahan pasir silika, karbon aktif serat daun nanas, serta zeolit, kemudian guna mengenali desain pemfilteran sehingga menghasilkan air bersih dengan kualitas terbaik. Metode penelitian menggunakan metode eksperimen. Peneliti memakai air sumur gali yang berasal dari Kawasan Mabar Hilir Kecamatan Medan Deli Provinsi Sumatera Utara. Media pemfilteran menggunakan pipa bening berdiameter 3 inci dengan panjang 80 cm. Komposisi pemfilteran sampel A, B, dan C sebesar 22%:45%:33%; 33,5%:33,5%:33%; dan 45%:22%:33%. Mutu air sumur gali saat sebelum pemfilteran telah penuhi standar air bersih kecuali pada parameter kadar Mn dan Fe. Dari hasil pengujian desain pemfilteran menunjukkan pada sampel C merupakan hasil yang optimal sebesar 92,3% dan 97,7%, sehingga menciptakan mutu yang penuhi PERMENKES RI Nomor 32 tahun 2017.Kata kunci : Filter air, pasir silika, karbon aktif serat daun nanas, dan zeolit.

Research has been done on the physicl test of charcoal briquettes made from tea stems (Camellia sinensis). This study aims to determine the physical characteristics of the charcoaI briquettes produced. This research is motivated by the increasing demand for human fuel, thus utilizing tea stems as the main ingredient in making briquettes. The sample variations used were tea tree trunk charcoaI and tapioca adhesive as an adhesive with a ratio of 90%:I0%, 80%:20%, 70%:30%, 60%:40%, and 50%:50%. The physical test carried out included water content, density, and calorific value. The results obtained from the physical test of biochar briquettes with the best quality approaching the quality standards of Indonesian briquettes were obtained on sample with a composition (70%:30%) with the value of water content, density, and calorific value, each of which was 5 .70%, 0.55 g/cm3, and (-) 7.62 cal/g.

Research has been carried out on the effect of adhesive variations on the heating value of briquettes made from tea leaf powder. This study aims to determine the quality of the briquettes produced, this research is motivated by the increasing need for human fuel, so that researchers use tea leaf powder as the main ingredient in making briquettes. The variation of the sample used was tea leaf powder using adhesives in the form of tapioca, wheat flour and molasses as adhesives. With a ratio of 80%:20% and 70%:30%. The analysis carried out is the Calorific Value test. The results obtained from the Calorific value test of briquettes with the best quality approaching the quality standards of Indonesian briquettes were obtained in sample C2 with a composition (70%:30%) which resulted in a heat absorption value of 112.86 cal/gram.

This research was conducted to utilize durian seed waste into activated carbon and aims to identify the characteristics of the durian seed activated carbon produced from the activation temperature alteration. With an experimental method with a quantitative approach, the process of making durian seed activated carbon was tested by carbonization using an oven at a temperature of 200 oC for 180 minutes, then temperature activation with alterations of 500, 600, and 700 oC was held for 120 minutes in the furnace, and after it was added with chemical activation by using a 1,5 M H2SO4 solution for 24 hours of immersion. The analysis seen is to test the water content, volatile matter content, ash content, bound carbon content, and to see the surface morphology of activated carbon using SEM (Scanning Electron Microscopy). The results of the test obtained values for water content (6,83 – 12,73%), volatile matter content (16,98 – 26,89%), ash content (7,85 – 12,04%), bound carbon content(61,66 – 75,17%), with an increase in the activation temperature there is a tendency to decrease the value of water content, volatile matter content, ash content, and there is an increase in the value of bound carbon content. And visible cavities on the surface of the activated carbon along with the increase in activation temperature.

Tujuan dari penelitian ini adalah untuk mengetahui pengaruh variasi waktu fermentasi larutan sari buah tomat merah terhadap kelistrikan bio-baterai saat diaplikasikan pada lampu LED merah. Variasi waktu fermentasi yang digunakan yaitu 48, 96, 144 dan 192 jam. Elektroda yang dipakai yaitu tembaga (Cu) sebagai katoda dan seng (Zn) sebagai anoda. Volume yang digunakan dalam penelitian ini adalah 100, 150, 200, dan 250 ml. Kelistrikan yang akan diteliti yaitu nilai tegangan listrik, arus listrik dan daya listrik. Pada penelitian ini diperoleh data hasil pengukuran kelistrikan yaitu nilai tegangan listrik maksimum terdapat pada waktu fermentasi 48 jam sebesar 2,01 Volt dan tegangan listrik minimum terdapat pada waktu fermentasi 144 jam, yaitu 1,69 Volt. Nilai arus dan daya listrik maksimum didapat pada waktu fermentasi 48 jam sebesar 0,49 mA dengan daya listrik 0,98 mW. Serta nilai arus dan daya listrik minimum terdapat pada waktu fermentasi 96 jam sebesar 0,11 mA dengan daya listrik 0,19 mW.

Telah dilakukan penelitian yang bertujuan untuk (i) mengetahui pengaruh kualitas air sumur gali sebelum dilakukan proses pemfilteran, (ii) mengetahui kualitas air sumur gali sesudah dilakukan proses pemfilteran, (iii) mengetahui komposisi karbon aktif biji salak, zeolit, dan pasir silika yang paling optimum agar diperoleh filter yang menghasilkan air bersih. Penelitian ini menggunakan air sumur gali yang berasal dari Desa Hessa Air Genting Kecamatan Air Batu Kabupaten Asahan Provinsi Sumatera Utara. Filter menggunakan bahan karbon aktif biji salak, zeolit, dan pasir silika. Zeolit dan pasir silika yang digunakan adalah zeolit dan pasir silika komersial. Karbon aktif biji salak diperoleh melalui proses pembakaran pada suhu 250ᴼC dan aktivasi pada suhu 700ᴼC selama 3 jam. Komposisi karbon aktif biji salak, zeolit, dan pasir silika yang digunakan adalah 0 cm: 10 cm : 10 cm, 5 cm: 10 cm : 10 cm, 10 cm: 10 cm : 10 cm, dan 15 cm: 10 cm : 10 cm. Dalam penelitian ini parameter yang diuji meliputi parameter fisika (bau, rasa, warna, TDS, kekeruhan, dan suhu) dan kimia (pH dan kadar logam Fe). Hasil uji sampel air sumur gali sebelum diterapkan metode pemfilteran belum memenuhi standar kualitas air bersih. Untuk parameter fisika yang belum memenuhi standar air bersih adalah warna, sedangkan parameter kimia yang belum memenuhi standar air bersih adalah pH dan Fe. Hasil uji sampel air sumur gali setelah diterapkan metode pemfilteran dengan karbon aktif biji salak, zeolit dan pasir silika telah memenuhi standar kualitas air bersih, kecuali pada parameter pH dan Fe pada Filter A. Komposisi karbon aktif biji salak, zeolit, dan pasir silika yang paling optimum agar diperoleh filter yang menghasilkan air bersih berdasarkan PERMENKES RI No.32 Tahun 2017 adalah 15 cm : 10 cm: 10 cm (Filter D). Karena kualitas air yang dihasilkan Filter D lebih baik dari Filter lainnya.

Research using the electrocoagulation method has been carried out to determine the results of the sample test results for BOD and COD parameters in palm oil mill effluent. The electrodes used n this method are aluminium electrodes with varying adapter voltages of 6, 9, and 12 Volts. Palm oil liquid waste used comes from PTPN IV Adolina Perbaungan. The results of the study showed that before the electrocoagulation method the BOD value obtained was 243 mg/l, while after the electrocoagulation method the best results were obtained at a voltage of 12 Volt with a value of 52,5 mg/l. The value obtained before the electorocoagulation method was carried out on the COD parameter was 649 mg/l and after the electrocoagulation method the best results were obtained at a voltage of 12 Volt, which was 110 mg/l. This shows that the parameter values of BOD and COD in processed waste have decreased and meet the wastewater quality standards for the palm oil industry, namelyb 100 mg/l and 350 mg/l. The higher the value of the applied voltage, the more optimal the levels of BOD and COD.

The need for an electrical energy source is currently a very necessary thing, therefore researchers conducted experiments on the use of pineapple peel (ananas comosus) extract as an electrolyte solution with a variety of electrodes. This research was conducted with the aim of generating voltage, electric current, and strength values. The measure of the holding capacity of the solution used were 50 ml, 100 ml, 150 ml, 200 ml, and 250 ml. The electrodes to be used are in the form of copper-zinc, copper-iron, and copper-aluminum pairs with each plate measurement of 4 cm × 7 cm, thickness of 0.2 mm. To determine the magnitude of the value of the voltage and current, a resistance is given in the form of an LED lamp. Based on the results of the research the pH measurement of the solution was 3.9. The test results obtained by the pair of Cu:Zn plates are the best compared to other pairs of plates, namely by producing a voltage of 1.59 Volts, a current of 0.28 mA, and an strength values of 0.44 mW with a volume of 250 ml. This is due to the influence of the volume of the solution and the electrodes used, that the more plates submerged in the solution, the greater the energy produced.

Research has been carried out to find out how the quality of dug well water before and after being filtered using activated carbon, zeolite, and silica sand, and to find out how the composition of the mixing of activated carbon, zeolite, and sand is to produce clean water with the most optimum quality for color parameters. based on PERMENKES RI No. 32 of 2017. This study uses dug well water from Sungai Segajah Jaya Village, Kubu District, Rokan Hilir Regency, Riau Province. The composition of activated carbon, zeolite, and silica sand used is 60%:20%:20%, 50%:25%:25%, and 40%:30%:30%. The test results of dug well water samples before applying the filtering method for color. The test results of dug well water samples after applying the filtering method with activated carbon, zeolite, and sand with a composition of 60%:20%:20%, 50%:25%:25%, and 40%:30%:30 %, for the color parameter has met the standard of clean water quality based on PERMENKES RI No. 32 of 2017. From the three variations in the composition of the filter material, the optimum composition of mixing activated carbon, zeolite, and silica sand in the filter was obtained with a composition of 40%:30%:30%. This is shown from the test results data, the results of sample D for color parameters are better according to the maximum limit standard allowed by PERMENKES RI No. 32 of 2017 concerning the requirements for clean water quality, namely 32 TCU.

Research has been carried out which aims to determine the test results of palm oil effluent samples on BOD and COD parameters before and after the electrocoagulation process using Al,Zn, and Fe electrodes. This research uses palm oil effluent from PTPN IV ADOLINA. The results of the BOD test before electrocoagulation were 243 img/l. The results of the BOD test after electrocoagulation with the Al electrode were 100 mg/l, the Zn electrode was i66.8 img/l, and the Fe electrode was 121 mg/l. The test results for COD levels before electrocoagulation were 649 mg/l.The test results for COD levels iafter electrocoagulation with Al electrodes were 350 mg/l, Zn electrodes were 178 mg/l, and Fe electrodes were 315 mg/l. From these electrode variations, ithe best results were obtained for testing the levels of BOD and COD of palm oil liquid waste on the Zn electrode. Key words: Electrode, Electrocoagulation, BOD, COD

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

A research has been carried out which aims to determine the subsurface structure using the geoelectric method in Panungkiran Village, Kab. Deli Serdang, Prov. North Sumatra Geoelectric data retrieval uses the Wenner configuration to determine the distribution and depth of subsurface structures in Panungkiran Village, Deli Serdang Regency. Prov. North Sumatra Data collection is 1 track with a length of 90 meters, Data processing in the study using MS office software Excel Notepad, and RES2DINV The results of the measurements consist of several types which are distinguished based on the range of resistivity values, namely in the range of 34.0-3188 2m interpreted by lithological layers topsoil (34.0-65.1 Ωm), sandstone (65.1-1252 Ωm) weathered travertine limestone (125-456 Ωm), fresh trvertine limestone (456-3188 Ωm), and resistivity >3188 Qm is interpreted as a cave at a depth of 9-12 meters.

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

Uji Fisis Paving Block dengan Penambahan Abu Cangkang Kerang Kepah (Polymesoda erosa). Penelitian ini adalah penelitian ekperimental yang bertujuan untuk mengetahui pengaruh penambahan abu cangkang kerang kepah (Polymesoda erosa) terhadap sifat fisis paving block. Data yang diperoleh merupakan data hasil penelitian yang dilaksanakan pada bulan september–oktober 2020 di Laboratorium UINSU-Medan. Sifat fisis yang diuji pada penelitian ini adalah densitas, daya serap air, dan porositas. Penggunaan abu cangkang kerang kepah sebagai pengganti sebagian semen dalam pembuatan paving block berpengaruh terhadap nilai densitas, daya serap air dan porositas. Pada setiap variasi campuran 5-15% menghasilkan penurunan nilai densitas yaitu sebesar 1,81, 1,77, dan 1,62 (g/cm3), mencapai nilai standar densitas beton ringan. Untuk nilai daya serap air pada setiap variasi campuran 0-15% mengalami peningkatan yaitu sebesar 5,88, 6,26, 7,37, dan 7,58%, telah memenuhi SNI 03-0691-1996. Kemudian untuk nilai porositas mengalami peningkatan pada variasi campuran 0-15% yaitu sebesar 9,95, 10,96, 13,41, dan 14,22%.

Penelitian ini bertujuan untuk mengetahui uji mekanik batako dengan penambahan serbuk gergaji kayu jati. Dalam penelitian menggunakan metode eksperimental, dengan pendekatan secara kuantitatif. Hasil penelitian menunjukkan bahwa nilai kuat tekan batako pada sampel tanpa penambahan serbuk gergaji kayu jati 0% : 64,71 kg/cm2 2% : 34.90 kg/cm2 dan 4% : 34.06 kg/cm2 memenuhi SNI 03- 0349-1989 mutu II, III dan IV. Nilai pada pengujian kuat impak cenderung mengalami penurunan yaitu 863 J/m2- 577,63 J/m2 tetapi masih termasuk ke dalam kategori batako normal. Berdasarkan penelitian Nia Nenshi Siregar (2013) nilai kuat impak pada batako normal 280 J/m2. Produk batako yang dihasilkan dapat digunakan sebagai bahan konstruksi bangunan seperti dinding penyekat dan lainnya.

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.

Research has been carried out on the analysis of the physical properties of paving blocks from egg shell powder. This study aims to determine the physical properties of water absorption, density and porosity in the resulting paving blocks. The samples used were eggshell powder, cement, and sand with a ratio of 0%:40%:60%, 5%:35%:60%, 10%:30%:60%, 15%:25%:60%, 20%:20%:60%. The FAS used was 0,56 and the drying time for the paving blocks was 28 days. The results of the analysis of the physical properties of paving blocks produced at 0% variation have a water absorption value = 8,08%, density = 2,29 g/cm3 and porosity = 13,31%, at 5% variation has a water absorption value = 8,10%, density = 2,18 g/cm3 and porosity = 13,94%, the 10% variation has a water absorption value = 8,63%, density = 2,17 g/cm3 and porosity = 14,41% , the 15% variation has a water absorption value = 8,83%, density = 2,16 g/cm3 and porosity = 14,94%, the 20% variation has a water absorption value = 9,10%, density = 2 ,14 g/cm3 and porosity = 16,82%. Keywords: Paving Block, Eggshell Powder, Physical Properties.

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.

The global need of biomaterial products especially in bone clinical application increases every year. The gold methods like autograft and allograft have some limitations in the application such as the availability of donor sites, antigenicity issues, the high cost, etc. To solve the problems, many researches and activities in the field of biomaterial have been conducted continuously in the past decades to develop the proper synthetic materials for bone substitutes which have properties similar to bone tissue. In this research, the synthesis of biocomposite for bone scaffold application prepared by freeze drying method has been done successfully. The materials used are biopolymer (alginate and chitosan) and bioceramics (carbonate apatite) with certain mixing variations. SEM result showed that the pores obtained by freeze drying method can mimic the pores of actual bone thus they will be able to resemble cells microenvironment, enhance interface interaction, and support cell proliferation. The existence of carbonate apatite on the scaffold’s surface can be observed with particle size of 0.05 – 1 μm and has been dispersed evenly. These results are in good agreement with FT-IR analysis that indicates the presence of PO43– functional group on the scaffold at wave numbers 569 and 1041.56 cm–1 and CO32– functional group at wave number 1411.89 cm–1. The in vitro biological evaluation of HeLa cells which exposed to extract solution of scaffold (in some variations of concentration) indicated that the scaffold obtained was not cytotoxic to the HeLa cells.

Research on the effect of electric voltage on the electrocoagulation process in reducing levels of heavy metals in water. This study aims to determine the metal content Fe (Iron) and Mn (Manganese) dug well water by varying the electrical voltage of 3, 6, 9, and 12 volts. this research use dug well water which come from Teluk Piyai Pesisir Village Kubu sub-district Rokan Hilir district Riau Province. Test results on the electrocoagulation method with electrical voltage 3 volt metal content Fe 0,002 mg/l and metal content Mn

A research has been done on the mechanical bricking test with the addition of bagasse ash. In this study, the tested bricks tested were compressive and flexural strength. The purpose of this study was to determine the effect of adding bagasse ash to the mechanical properties of the concrete brick. The percentage variation of bagasse ash, cement, and sand are 0%:30%:70%, 5%:25%:70%, 10%:20%:70%, 15%:15%:70%, 20%:10%:70% with Water Cement Ratio of 0.5 in all variations. The addition of bagasse ash as a substitute for cement significantly affected the characteristics of the concrete brick. With the addition of bagasse ash in a mixture of 5-20% causes the compressive strength to decrease. While the flexural strength has increased in the variation of the mixture of 5-10% and has decreased in the variation of the mixture of 15-20%. The most optimal composition of mixing bagasse ash, cement, and sand is at 5% mixture variation for compressive strength and flexural strength testing because it meets SNI 03-0348-1989 standards. Whereas the other mixed variations are not optimal. Keyword s : Bagasse ash, Compressive Strength, and Flexural Strength .

The kitchen is one of the places most concerned by every community because the biggest fire potential in the house lies in the kitchen, the source of fire that often causes fires in the kitchen is a stove and gas. Therefore we need a design of a kitchen security system based on the ATmega32 microcontroller using flame sensors, MQ-2 and MQ-6. This study aims to produce a performance tool that will detect any movement of fire, gas, and smoke using an Early Warning System. The warning in the form of an alarm sounds, the fan turns, and the door opens automatically. Sensor detection is designed with 4 conditions namely Normal, Caution, Alert and Danger. The results of testing using the Flame sensor found a wave range from 22 nm to 1022 nm from normal to hazardous conditions, the MQ-2 found the results of testing from the ADC (Analog Digital Converter) with concentrations from 0 ppm to 130 ppm from normal to hazardous conditions, and the MQ-6 test results were obtained from the ADC (Analog Digital Converter) with concentrations from 0 ppm to 520 ppm from normal to dangerous conditions. Keyword s : Kitchen, ATmega32, Flame sensor, MQ-2, and MQ-6.

A research has been conducted on the comparison of the value of burnt shrinkage and porosity of bricks by adding a mixture of coconut husk ash and rice husk ash. The purpose of this study is to determine the effect of variations in the addition of coconut husk ash and rice husk to the value of burnt shrinkage and porosity of bricks. Porosity testing was carried out due to the addition of a mixture of coir ash and rice husk to produce porous bricks. Variations in the percentage of clay with a mixture (coconut husk ash and rice husk ash) include 100%:0%, 95%:5%, 90%:10%, 85%:15% and 80%:20%. The results obtained for the value of burnt shrinkage from the addition of rice husk ash in brick making results are smaller than the addition of coconut coir ash. The results of the shrinkage value of the addition of coconut coir ash and rice husk already meet the SNI 15-2094-2000 standards that is 20%. With large porosity values exceeding SNI 15-2094-2000 standards, the suggested bricks are used as an inner wall and cannot be used as a face wall. Keyword s : burn t shrinkage, coconut husk ash, porosity , and rice husk ash .

This research aimed to show on electricity from Durian skin waste nanomaterials. The compounds that abundant in Durian skin waste are phosphate compounds (PO4). This phosphate compound makes the Durian skin waste has a high and unique electrical properties. Durian skin waste was synthesized using co-precipitation method to obtain LKD nanopowder with an average crystal size of 5 nm. LKD was dried at 250 °C and then washed with 100 ml distilled water and measured the electrode with variations of Pb, Al, Zn, Fe and Cu. Obtained the electrical properties as much five times greater than before, which is an average of 6.5 Volts. It was concluded that the electrical properties of Durian skin waste will increase when the crystal size is smaller and Durian skin waste can be as bio-batteries. From electrode variations was obtained that the Zn electrode had a greater electrical voltage than the Al, Fe, Pb and Cu electrodes.