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"Latar belakang: Saat ini debu tepung masih dianggap sebagai bahan yang tidak berbahaya/debu inert, sementara pada industri tepung terigu PT.ISM BSFM terdapat tendensi peningkatan gangguan saluran napas atas maupun saluran napas bawah. Penelitian bertujuan mencari hubungan antara gangguan faal paru pada pekerja dengan pajanan debu tepung dan faktor lain yang berhubungan, prevalensi keluhan serta prevalensi penyakit paru kerja.Metode: Penelitian menggunakan desain studi Cross sectional internal kompartif terhadap dua kelompok pekerja yang terpajan rendah dan terpajan tinggi berdasarkan hasil pengukuran personal dust sampler(debu respirable). Studi dilakukan dengan mewawancarai 119 responden memakai kuesioner Pneumobile project Indonesia 1992, mengukur faal paru dengan spirometri dan pengukuran Arus puncak ekspirasi.Hasil dan Kesimpulan: Kadar debu di bagian pengemasan dan penggilingan sangat tinggi mencapai 3 kali NAB. Terdapat penurunan faal paru berupa restriksi pada 37 % responden dan obstruksi 7,5%, di mana terdapat hubungan yang bermakna antara penurunan fungsi paru dengan status gizi, pekerja yang terpajan tinggi, lama merokok, umur dan lama kerja. Prevalensi keluhan batuk kronik 21,8 %, berdahak kronik 13,4 % dan sesak napas 18,5 %, sementara prevalensi penyakit paru kerja didapat 4,2 % responden yang menderita bronkitis kronik dan 14,3% asma di mana 1,7 % merupakan asma kerja.

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Back ground: Today grain flour dust is still assumed as nontoxic dust, while several respiration disease (upper and low) are increase at PT.ISM BSFM the biggest grain mill in Indonesia. The goal of this study was to identify relation between the decrease of lung function and the exposure of grain flour dust, with some other related factor. To find prevalent of symptom and prevalent of occupational lung disease.

Method: Design of the study was a Cross-sectional study, with internal comparative of the two group workers (high exposure and low) that base on result of measurement of personal dust sampler (respirable dust). A simple working survey using Pneumobile Indonesia questioner was carrying out to 119 respondents, measurement lung function by spirometri and peak flow expiration.

Results and Conclusion: Study finding the high exposure of dust at the packing unit and milling unit, the concentration is 3 time greater than TLVs. Result of the lung function measurement found 37 % respondent were restriction and 7.5% obstruction, this respondent have significant relation with their body mass index, working in the high exposure place, length time of smoking, age and length time of working. Prevalent of chronic cough 21.8 %, chronic sputum 13.4 % and breathing difficulty 18.5 %, while prevalent of occupational lung disease were 4.2 % respondent with choric bronchitis and 14.3% asthma included 1.7 % occupational asthma."

"Purpose of Research (specific objective and/or statement of hypothesis in around 300 to400 words. Please try to avoid using an additional page). Zry-4 is an alloy of Ziconium (Zr) with alloying elements of Fe,Cr, and Sn with weight percentage of 0.2%, 0.07% and 1.5% respectively. This alloying element addition is intended to improve the mechanical properties as well as Zirconium, that is corrosive resistance at high temperature. Besides the alloying elements, the micro structural morphology of Zry-4, as results of thermomechanic treatment process, also an active role to determine mechanical, physical and corrosion properties. This alloy is used as structure and cladding materials for Pressurized water Reactor (PWR) nuclear fuel element. Zirconium alloy of Zr-702 will also be used for chemical engineering devices due to its high corrosion resistance in acid and alkali liquid as well as at high temperature. Examples of device are : Distillation Column, Reactor, Pump Housing and Heat exchanger and Heating coil due to mechanical properties at high temperature. Some researchs have been done previously to observe changes of mechanical and corrosive properties of Zry-4 with solution treatment 0-phase, but unfortunately they are not continued between deformation degree and grain size with new precipitate is obtained.In this research we plan to carry out a cold deformation process of 0-quenching result and be continued with annealing process. From the process results we will observe the morphology of micro structure of Zry-4. This process will enable to determine the deformation level, time and temperature annealing to obtain a certain microstructure according to the desired mechanical properties (Microhardness). Results of research can hopefully be used as input in the working process of Zry-4.Optical Microscopy, Transmission Electron Microscopy and X-Ray Diffraction will be used in the microstructure observation."

"The result of a numerical simulation of a spouted bed grain dryer based on the Eulerian Multiphase Model are presented....."

"Banyak industri komponen otomotif yang menggunakan paduan AC4B dalam proses pengecoran cylinder head karena kelebihannya di antara paduan aluminium lainnya. Kelebihan paduan AC4B antara lain ringan, kuat, tahan korosi dan mampu dilakukan proses perlakuan panas. Cylinder head memiliki dimensi yang cukup rumit sehingga adanya perbedaan kecepatan pembekuan antara bagian tebal dan tipis menyebabkan terjadinya penyusutan dan kebocoran pada cylinder head. Dengan penambahan grain refiner (Ti) diharapkan terciptanya nukleat (partikel AlTi3) secara merata pada bagian tebal dan tipis sehingga menghasilkan pembekuan yang seragam (mengurangi terjadinya penyusutan dan bocor) serta menghasilkan ukuran butir yang lebih kecil. Masalah lain yang sering muncul adalah efek fading karena durasi LPDC yang cukup lama.Penelitian ini bertujuan mempelajari pengaruh penambahan grain refiner 0,05 wt.% Ti dalam bentuk serbuk (fluks) terhadap karakteristik paduan AC4B serta mempelajari waktu fading selama 1 sampai 4 jam dengan metode pengecoran LPDC. Sampel pengujian dibedakan menjadi sampel bagian tipis (stud bolt) dan bagian tebal (daging). Hal ini untuk mengetahui pengaruh penambahan titanium terhadap laju pembekuan cepat dan lambat. Kedua sampel tersebut dietsa untuk menghitung jarak DASnya dan dilakukan pengamatan mikrosruktur setelah itu menguji kekerasan. Sampel uji tarik dan uji komposisi diambil pada awal dan akhir pengecoran. Sampel pengamatan SEM dan EDS diambil pada bagian tebal dan dilakukan untuk mengetahui fasa intermetaliknya.Hasil penelitian menunjukkan bahwa penambahan 0,05 wt.% Ti menghasilkan kekerasan yang melebihi standar JIS untuk paduan AC4B (80 BHN) yaitu berkisar antara 87,2 sampai 92,9 BHN. Efek fading tidak terjadi baik pada bagian tebal maupun pada bagian tipis. Hal ini terlihat pada perubahan kekerasan yang terjadi selama 4 jam tidak terlalu signifikan. Adanya sedikit pengadukan pada mesin LPDC dicurigai yang menyebabkan tidak terlihatnya efek fading.Hasil uji tarik mengalami penurunan dari 165,8 MPa menjadi 162,9 MPa serta hasil perpatahanya getas. Fasa yang terbentuk adalah fasa intermetalik Al2Cu yang berwarna putih, fasa intermetalik β-Al15(Fe,Mn)3Si2 yang berwarna abu abu, fasa AlSi yang berwarna gelap dan matriks aluminium. Tingkat kegagalan cylinder head cukup tinggi yaitu 8,3 %. Hal ini diperkirakan karena kurang banyaknya jumlah grain refiner (Ti) yang digunakan pada proses pengecoran cylinder head dalam menanggulangi cacat bocor.

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Many of automotive manufacturing used AC4B alloy for producing cylinder head because their benefical characteristics such as light, strong, good corrosion resistance and heat treateable. Cylinder head has complex dimension enough therefore the difference of cooling rate may lead to shrinkage and leakage of cylinder head. By adding grain refiner (Ti), nucleat AlTi3 are expected to uniformly distribute to thin and thick parts of cylinder head. The uniform cooling can reduce shrinkage, leakage and grain size.

This research aims for studying the addition of grain refiner 0.05 wt.% Ti (flux) of AC4B characteristics and studying fading efect in 1 to 4 h with Low Pressure Die Casting method. Testing sample is taken from thin (stud bolt) and thick parts to study effect of titanium on solidification rate on each part. Both of samples were etching for calculating the DAS and microstructure examination then evaluate hardness testing. Tensile and compotition samples were taken at start and ending of casting process. SEM and EDS samples were used to examine the intermetallic phases.

The research show that addition of grain refiner with 0.05 wt.% Ti was increasing hardness number about 87.2 to 92.9 BHN beyond JIS standard of AC4B (80 BHN). Fading efect did not occur at thick and thin sample. This is confirmed by the hardness?s changing in four hours was not significant. Agitation of LPDC mechine suspected the hardness of thick and thin sample were not significant.

Tensile test was decreasing from 165.8 MPa to 162.9 MPa and has a brittle fracture. Phases that occurred are white Al2Cu, grey β-Al15(Fe,Mn)3Si2, dark AlSi, and aluminium matrix. Reject level of cylinder head is 8.3 %. This predicted cause by insufficient of using grain refiner (Ti) for producing cylinder head to overcome leakage reject level."

"Paduan AC4B (standar JIS) atau paduan 333.0 as-cast (standar AA) secara komersial banyak digunakan sebagai bahan baku pembuatan komponen pada industri manufaktur otomotif. Diketahui sering terjadi reject karena kegagalan yang terjadi pada pembuatan komponen otomotif, diantaranya adalah shrinkage dan porosity. Pendinginan yang tidak stabil atau tidak merata dapat menyebabkan shrinkage yang berimplikasi pada menurunnya kekuatan dari produk cor. Dengan penambahan grain refiner sebagai nuklean, maka pendinginan dapat lebih terkontrol sehingga butir-butir logam menjadi lebih halus dan dihasilkan kekuatan mekanis yang lebih baik. Efek fading perlu dikontrol saat penambahan grain refiner. Keefektifan grain refiner semakin turun seiring dengan meningkatnya waktu.Pada penelitian ini dilakukan penambahan grain refiner 0.019 wt.% Ti dalam bentuk serbuk fluks setelah proses degassing. Proses pengecoran dilakukan pada Low Pressure Die Casting (LPDC) dalam rentang 120 menit dengan 4 variabel waktu fading setiap 30 menit : 30 menit, 60 menit, 90 menit, dan 120 menit. Sampel pengujian diambil pada bagian yang tebal dan bagian tipis dari cylinder head hasil proses LPDC untuk mengetahui pengaruh penambahan titanium terhadap laju pembekuan pada setiap variabel waktu fading. Dilakukan pengujian tarik dan kekerasan untuk mengetahui perubahan sifat mekanis berupa perubahan nilai kekuatan tarik, elongasi serta kekerasan. Pengamatan mikrostruktur untuk mengamati perubahan mikrostruktur yang terjadi akibat penambahan titanium. Pengamatan struktur dengan SEM dan EDAX dilakukan untuk mengetahui fasa yang terbentuk.Hasil penelitian menunjukkan bahwa penambahan grain refiner dengan kadar 0.019 wt.% Ti meningkatkan kekuatan tarik, kekerasan serta menurunkan nilai Dendrite Arm Spacing (DAS). Terjadi kecenderungan peningkatan kembali nilai DAS sehingga berdampak pada penurunan sifat mekanis setelah 30 menit karena berkurangnya keefektifan grain refiner. Menurunnya keefektifan grain refiner ini menunjukkan terjadinya efek fading. Fenomena ini diasumsikan karena pengendapan partikel AlTi3 pada dasar furnace seiring bertambahnya waktu karena perbedaan densitas partikel grain refiner (~3,35 gr/cm3) dan aluminium cair (~2.3 gr/cm3).

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AC4B alloys (JIS standard) or 333.0 as cast alloys (AA standard) are widely used commercially as raw materials for parts manufacturing on automotive industries. Reject is often occurred and caused by shrinkage and porosity. Uncontrolled solidification could cause shrinkage which leads to lowering the strength of cast product. With the addition of grain refiner as nucleant, solidification rate can be controlled resulting in finer grain and better mechanical properties. Fading effect must be controlled at grain refiner addition. Grain refiner effectivity is lower as time increases.

On this research grain refiner addition in flux powder was added at 0.019 wt. % Ti after degassing process. Casting was done in Low Pressure Die Casting (LPDC) in 120 minutes with 4 variables fading time every 30 minutes : 30 minutes, 60 minutes, 90 minutes, and 120 minutes. Samples was taken from thick and thin parts from cylinder head to observe titanium addition on solidification rate on every fading time variables. Tensile test and hardness test was conducted to observe changes in mechanical properties in tensile strength, elongation and hardness value. Microstructure examination was performed to observe changes in microstructure after titanium addition, while SEM and EDAX observation was conducted to read phases that occur.

The experiment results shows that 0.019 wt. % grain refiner addition increased tensile strength, hardness,and decreased DAS value. After 30 minutes, there are increase in DAS value and decrease in mechanical properties because decrease of grain refiner effectivity. The decrease of grain refiner effectivity shows the fading effect. This phenomenon was assumed by the settling of Al3Ti on the bottom of the furnace as time increases because of the difference in grain refiner particle density (~3,35 gr/cm3) and molten aluminium (~2.3 gr/cm3)."

"World demand for superior rice grain quality tends to increase. One of the criteria of apprearance quality of rice grain is grain shape. Rice consumers exhibit wide preferences for grain shape but most Indonesia rice consumers prefer long and slender grain...."

"Sedimentasi merupakan kejadian yang alami dimuka bumi ini, permasalahan sedimen seringkali terjadi pada sebuah daerah aliran sungai. Dalam Kali Lumajang masalah sedimen sangat mempengaruhi sekali terhadap sistem hidrologi yang ada dihilirnya. Masalah utama dari sedimen adalah berasal dari mana sedimen tersebut ada. Penelitian mengenai wilayah sumber sedimen bertujuan untuk mengkaji seberapa besar kejadian suspended sedimen serta mencari wilayah mana yang menjadi sumber material sedimen didalam DA Kali Lumajang. Analisis grain size, analisis regresi dan analisis overlay dalam sistem informasi geografis sangat diperlukan untuk menjawab wilayah sumber material sedimen. analisis grainsize digunakan untuk mengetahui kandungan material penyusun sedimen dan akan diregresikan dengan debit aliran yang terjadi sehingga akan didapatkan hubungan korelasi antar keduanya. Kemudian analisis overlay digunakan untuk menguatkan asumsi yang ada tentang kesimpulan awal wilayah sumber material sedimen. Proses interpretasi citra mengenai sebaran tanah terbuka adalah sangat penting sebagai modal awal untuk penentuan wilayah sumber material sedimen dengan melihat karakteristik material penyusun sedimen. Hasil kajian menunjukkan bahwa terdapat korelasi yang kuat antara konsentrasi sedimen dengan debit aliran dengan persamaan Ks = 5,112 Qw ? 6,083. Kemudian wilayah sumber material sedimen tersebar pada wilayah yang memiliki nilai indeks vegetasi rendah, bentuk medan yang bergelombang hingga curam dan memiliki tingkat bahaya erosi dari normal hingga sangat berat.

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Sedimentation is a natural occurrence in the earth, the problem of sediments often occur on a local river. In time, the sediments Lumajang influence of the hydrology of the system have in downstream. The main problem is derived from the sediments from which the sediment is present. Research on the sediment source area aims to assess how big the incident and suspended sediments explore areas which are a source of material in the sediments Lumajang watershed Times. Grain size analysis, regression analysis and overlay analysis in geographic information system is necessary for the source material of sediments. Grainsize analysis used to determine the actual material it will be regression of sediments and with the water flow going so that the relationship will be established correlation between the two. Then the overlay analysis is used to strengthen the assumption that no conclusions about the initial source material sediments. The process of interpretation of the image of the open land is very important as the initial capital for the determination of the source material with the sediment characteristics of the material to see it sediments. Results of the study indicate that there is a strong correlation between the concentration of sediments with the debit flow with equality Ks = 5.112Qw - 6.083. Then the source material sediments in the region spread the vegetation has a lower index value, the form of the wave field to the steep and has a high danger of erosion from normal to very heavy."

"It is knoewn that the most effective way to improve mechanical properties of steels is by microstructural refinement....."