94 research outputs found
ANALISIS FISIK PENGARUH LIMBAH ABU AMPAS TEBU SEBAGAI SUBSTITUSI PARSIAL PADA BETON NORMAL
Salah satu tantangan yang dihadapi para ahli teknologi beton adalah bagaimana memanfaatkan limbah industri sebagai bahan tambah atau substitusi parsial pada beton normal. Dalam hal ini, para ahli mengkaji dan meneliti tentang pemanfaatan limbah industri yang ada agar dapat dimanfaatkan terutama bahan limbah abu ampas tebu industri pabrik gula. Hal ini menjadi salah satu dari sekian solusi penanganan limbah yang ada dimasyarakat. Tujuan dari penelitian ini adalah untuk mengetahui pengaruh substitusi abu ampas tebu terhadap agregat halus pada beton normal secara fisik dan mekanik. Bahan yang digunakan dalam penelitian ini terdiri dari semen Portland Composit Cement (PCC), agregat halus Sungai Je’ne’berang Gowa, agregat kasar yang berasal dari batu pecah Bili-Bili dan air PDAM dan material limbah abu ampas tebu sebagai substitusi agregat halus berasal dari Pabrik Gula Kabupaten Takalar, Provinsi Sulawesi Selatan. Alat yang digunakan pada penelitian ini sebelumnya telah diperiksa kondisi dan kemampuannya serta telah dikalibrasi terlebih dahulu. Benda uji silinder dibuat dengan cara memasukkan beton segar dari molen ke dalam cetakan silinder ukuran 15 cm x 30 cm yang telah diolesi minyak pelumas. Pengisian ini dilakukan secara bertahap, yaitu tiap sepertiga bagian dilakukan penumbukan dengan tongkat baja sebanyak ± 25 kali. Setelah 24 jam, cetakan dibuka kemudian dilakukan perawatan dengan direndam di dalam bak air selama 28 hari. Benda uji beton normal sebanyak 9 sampel dan benda uji yang disubstitusi abu ampas tebu sebanyak 9 sampel. Berdasarkan hasil penelitian didapatkan nilai berat volume beton untuk komposisi pencampuran ampas tebu 8% yaitu 701,41 kg/m3, 10% yaitu 701,41 kg/m3 dan 12% yaitu 690,10 kg/m3 dari ketiga komposisi tersebut diperoleh berat volume beton yang maksimal yaitu komposisi pencampuran ampas tebu 12%.
Fate of phthalic acid esters during composting of both lagooning and activated sludges
Among the phthalic acid esters (PAEs) targeted by the United States Environmental Protection Agency (USEPA) as priority pollutants, di-ethyl-hexyl phthalate (DEHP) is the major pollutant identified at high concentration level in lagooning sludge (LS), at about 28.67 mg/kg, andin activated sludge (AS), at about 6.26 mg/kg. Other phthalic acid esters, such as di-butyl phthalate (DBP) and di-methyl phthalate (DMP) show very low concentrations. During sludge composting, after the stabilization phase, the subsequent appearance of DEP and then DMPoccurred indicating that microbial metabolism begins by alkyl side-chain degradation before aromatic ring-cleavage. The appearance andaccumulation of PAEs with a short alkyl side-chain in the last stages of AS and LS composting is suggested originating from the degradationof phthalates with a much long side-chain. The DEHP showed a rate of biodegradation that follows a first-order kinetic model during composting of both AS and LS. The calculated DEHP half-lives are 45.4 days for LS and 28.9 days for AS. The better DEHP biodegradationrate (2.4 Â 10À2 dayÀ1) have been observed in the case of AS composting compared to LS compost (1.53 Â 10À2 dayÀ1). The mono-ethyl-hexyl phthalates MEHP has been shown to follow the same order of biodegradation as DEHP indicating that the same mechanism is followed(hydrolysis or dealkylation of each DEHP side-chain). Composting could be suggested as a detoxification process for the removal of PAEs(mainly DEHP) from sludges after a sufficient time of treatment to provide a safe end product
The effect of black and green-tea extracts on dental-plaque forming Streptococci
زمینه و هدف: چای از پرمصرفترین نوشیدنیها در ایران است. اثرات ضد میکربی چای روی میکروارگانیسمهای متعددی به اثبات رسیده است و یافتن فرآورده های طبیعی مانند مشتقات چای، که فاقد مخاطرات بر سلامت انسان باشند جهت کاهش ارگانیسم های پاتوژن ضروری بنظر می رسد. لذا این پژوهش با هدف بررسی اثر عصاره چای سیاه و سبز ایرانی بر استرپتوکوکهای دهانی (استرپتوکوکوس موتانس، استرپتوکوکوس میتیس و استرپتوکوکوس سنگوییس) و اثر بازدارندگی آنها از تشکیل بیوفیلم، روی عوامل ایجاد کنندۀ پلاکهای دندانی و پوسیدگی دندان انجام شد. روش بررسی: در این مطالعه تجربی پس از عصاره گیری نمونه ها با حلال متانول50 و جدا نمودن مجدد در فاز اتیل استـــات، عصاره ها توسط فیلتر 44/0 میکرون استریل شده و در 4 درجۀ سانتیگراد نگهداری شدند. از روش تهیۀ رقت های متوالی در محیط مایع برای محاسبۀ حداقل غلظت بازدارندگی و با تلقیح باکتریها به درون ارلن های حاوی لامهای شیشهای برای سنجش تشکیل بیوفیلم استفاده شد. تشکیل بیوفیلم با کشت نمونه از روی لام ها و شمارش کلنیها و همچنین مقایسۀ آنها در زیر میکروسکوپ فاز کنتراست با نمونۀ شاهد (محیط های تیمار نشده) مقایسه گردید. میانگین اندازه گیریها در سه بار تکرار بیان و خطاها در هر نمونه با استفاده از آزمون آماری استاندارد (ANOVA) تعیین گردید. یافته ها: میکروسکوپ فاز کنتراست کاهش فوق العاده ای را در چسبیدن میکروارگانیسم های تیمار شده به یکدیگر در مقایسه با نمونۀ شاهد نشان داد. در غلظت 1 میلی گرم در میلی لیتر از عصارۀ چای سیاه بیوفیلم تشکیل نشد و غلظت 5/1 میلی گرم در میلی لیتر از عصارۀ چای سبز نیز بازدارندۀ کامل تشکیل بیوفیلم بود. عصاره های چای سیاه و سبز، به ترتیب در غلظت 5/2 و 3 میلی گرم در میلی لیتر اثر باکتریسایدی روی استرپتوکوکوس موتانس، استرپتوکوکوس میتیس و استرپتوکوکوس سنگوییس داشتند. نتیجه گیری: عصاره های چای به هر دو صورت چای سیاه و سبز خاصیت باکتریسایدی داشتند و اثر ضد میکربی چای سیاه بر روی استرپتوکوک های دهانی و ممانعت از تشکیل بیوفیلم توسط آنها بیشتر از چای سبز است
Impact of β-Globin Mutations on Outcome of Matched Related Donor Hematopoietic Stem Cell Transplantation for Patients with β-Thalassemia Major
AbstractThe clinical outcome of hematopoietic stem cell transplantation (HSCT) for patients with β-thalassemia major (β-TM) can be affected by several factors. We investigated the influence of β-globin gene mutation in patients with β-TM on the clinical outcome of HSCT and conducted a prospective study of consecutive β-TM patients who underwent allogeneic HSCT at our center. Among 87 included patients, 62 (71%) had homozygous and 25 (29%) had compound heterozygous β-globin gene mutations. Intervening sequence II-1 appeared to be the most common mutation, with an occurrence rate of 33% in β-globin alleles. With a median follow-up of 12 months, the thalassemia-free survival and overall survival probabilities were 83% (standard error, 4%) and 90% (standard error, 3%), respectively. Overall survival was not found to be associated with the β-globin gene mutation status, but thalassemia-free survival was significantly improved in patients with homozygous mutations compared with patients with compound heterozygous mutations in univariate (91.2% versus 64.0%, P = .009) and multivariable (hazard ratio, 3.83; P = .014) analyses. This is the first report on the impact of β-globin mutation status on the outcome of β-TM after allogeneic HSCT and helps to better illustrate the course and prognosis of β-TM after transplantation
The stochastic counterpart of conservation laws with heterogeneous conductivity fields: application to deterministic problems and uncertainty quantification
Conservation laws in the form of elliptic and parabolic partial differential
equations (PDEs) are fundamental to the modeling of many problems such as heat
transfer and flow in porous media. Many of such PDEs are stochastic due to the
presence of uncertainty in the conductivity field. Based on the relation
between stochastic diffusion processes and PDEs, Monte Carlo (MC) methods are
available to solve these PDEs. These methods are especially relevant for cases
where we are interested in the solution in a small subset of the domain. The
existing MC methods based on the stochastic formulation require restrictively
small time steps for high variance conductivity fields. Moreover, in many
applications the conductivity is piecewise constant and the existing methods
are not readily applicable in these cases. Here we provide an algorithm to
solve one-dimensional elliptic problems that bypasses these two limitations.
The methodology is demonstrated using problems governed by deterministic and
stochastic PDEs. It is shown that the method provides an efficient alternative
to compute the statistical moments of the solution to a stochastic PDE at any
point in the domain. A variance reduction scheme is proposed for applying the
method for efficient mean calculations
Degradasi Mekanik Beton Mutu Tinggi Pasca Bakar
Research on the effect of temperature on concrete is still a hot topic. The effect of temperature was measured on its mechanical properties and analyzed using descriptive statistical analysis. The desire of researchers to know accurately the shape, description, and influence of temperature on concrete is something that still needs further research. The researchers began to research by making concrete test objects which were then burned directly in the furnace. After that, testing is done on the test object in the form of compressive strength. The research that was carried out was the remains of a burning building. But so far the assessment research has not yet found a strong starting point. Broadly speaking, the problem examined in this study is that researchers want to know the magnitude of high quality concrete mechanical degradation after being burned at a certain temperature and compared with high quality concrete that is not burned. These results are expected to provide a basis for the repetition of buildings that use high quality concrete that has been burned. The results of the mechanical degradation test reviewed were the average compressive strength of high quality concrete at a normal temperature of 53.46 MPa, a temperature of 100oC of 34.93 MPa, a temperature of 300oC of 29.76 MPa, a temperature of 600oC of 25.57 MPa
The effect of distribution supply fertilizer on rice production improvement in Gorontalo City
The purposes of this research are to: 1) analyze the distribution of subsidized fertilizer in Gorontalo City, 2) analyze the distribution of subsidized fertilizers partially (right price, right amount, and time) to increase rice production in Gorontalo City. The study conducted in Gorontalo City with a sample number of 95 farmers. The research method used is survey method. Data analysis used is multiple linear regression analysis. The results showed that there are two distributors fertilizer in Gorontalo City is PT. Indonesian Trade Company (PT PPI) and Indonesian Trade Cooperative (KPI), and 5 authorized retailers which are distributing subsidized fertilizer is Kios Tani Lestari, Anugerah Tani Kios, Saprodi Tani Kios, Cahaya Tani Kios and Bunga Tani Kios. PT. PPI is responsible for distributing NPK, SP36 and ZA fertilizers while KPI is responsible for the distribution of Urea fertilizer. Distribution of subsidized fertilizer on rice farming simultaneously have a positive and real effect on increasing rice production, while partially that have positive and real influence that is Right price, Right amount and time to increase rice productio
SAFETY ASSESSMENT OF LINUM USITATISSIMUM (LINN.) INGESTION IN NEW ZEALAND RABBITS
Background: The therapeutic safety of herbal medicine is a major concern for consumers and users. After studying the effects of linseed on hair
growth in rabbits, the turn is to evaluate its safety by the observation of some clinical, biological and anatomo-pathological aspects.
Materials and Methods: A study was conducted during a period of three months on two groups of rabbits (control and test). Test group daily
received feed supplemented with 3g of ground linseed while the control animals received the same feed without any additives. Weekly, rabbits
were weighed and monthly blood samples were taken. By the end of the trial, liver and kidneys biopsies were analyzed for histological and
cytological lesions.
Results: There was no significant improvement in weight gain in the test group rabbits, in which biochemical parameters had differentially
evolved with a decrease in their Glycemia and cholesterolemia. There were also no modifications in their serum hepatic and renal marker
enzymes and their liver and kidneys exhibited noticeably normal histology without any anatomically detectable anomalies.
Conclusion: These findings confirm that prolonged linseed ingestion in rabbits is safe
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