Physic

Apakah Anda pernah menyadari bahwa pelangi merupakan fenomena alam yang terjadi dengan proses fisika yang sangat menarik untuk dipelajari. Maka, di sini akan di jelaskan bagaimana paoses terjadinya pelangi itu. Pelangi merupakan suatu busur spektrum besar yang terjadi karena pembiasan cahaya matahari oleh butir-butir air. Pelangi adalah gejala optik dan meteorologi berupa cahaya beraneka warna saling sejajar yang tampak di langit atau medium lainnya. Di langit, pelangi tampak sebagai busur cahaya dengan ujungnya mengarah pada horizon pada suatu saat hujan ringan. Pelangi juga dapat dilihat di sekitar air terjun yang deras, biasanya fenomena ini terjadi ketika udara sangat panas tetapi hujan turun rintik-rintik. Kita dapat melihat jelas fenomena ini, jika kita berdiri membelakangi cahaya matahari.

Skema mesin turbofan model high-bypass. Sumber: https://en.wikipedia.org) Dari gambar skema mesin turbofan di atas terlihat ada 2 rangkaian (spool), yang berwarna ungu adalah rangkaian tekanan tinggi (high-pressure spool) sedang yang berwarna hijau adalah rangkaian tekanan rendah (low-pressure spool).

Different from most previous work in statistical multiplexing that consider only fixed transmission rates, we consider statistical multiplexing in networks with adaptive transmission rates such as DSL broadband access networks. The problem is to determine the buffer space and transmission bandwidth allocations among various traffic flows, taking into consideration of the traffic characteristics and QoS requirements, as well as user interactions at the physical layer. We propose a class of Alternate Maximization (AM) algorithms (AM-D and AM-M), which solve the statistical multiplexing problem for both delay insensitive Data traffic and delay sensitive Multimedia traffic. We use mathematical tools such as effective bandwidth and Chernoff's bounds to transform a statistical multiplexing problem into a series of problems that can be solved using our recently proposed Autonomous Spectrum Balancing (ASB) algorithm, which was originally designed for spectrum management in the DSL physical layer. As part of the AM-M algorithm, we also develop an Iterative Hypothesis Testing (IHT) algorithm that adaptively allocates transmission bandwidth among a mixed of data and multimedia flows. The proposed algorithms have provable convergence, low complexity, and admit as much as 200% of the number of flows of a system with no spectrum management, and achieve a statistical multiplexing gain of 180%.

Child development is a lifelong process being associated with a series of specific changes which result to be more visible and vigorous in childhood. Achievements in technology with which the present-day children are being grown up as well as the advance of science have brought a challenging reality for parents, teachers and adults concerning quests and dilemmas they are being faced with in the course of their children’s growth and development. In these terms, this study aims to convey some know-how and methodical guidance for both parents and teachers being involved with pre-school children education, mainly related to some of the main fields of the child’s development. I think and hope that treated issues concerning pre-school children thorough development will serve as guidance and contribution to their healthy growing and education.

A new UV spectrophotometry based method for determining the concentration and carbon content of carbohydrate solution was developed. This method depends on the inherent UV absorption potential of hydrolysis byproducts of carbohydrates formed by reaction with concentrated sulfuric acid (furfural derivatives). The proposed method is a major improvement over the widely used Phenol-Sulfuric Acid method developed by DuBois, . In the old method, furfural is allowed to develop color by reaction with phenol and its concentration is detected by visible light absorption. Here we present a method that eliminates the coloration step and avoids the health and environmental hazards associated with phenol use. In addition, avoidance of this step was shown to improve measurement accuracy while significantly reducing waiting time prior to light absorption reading. The carbohydrates for which concentrations and carbon content can be reliably estimated with this new rapid Sulfuric Acid-UV technique include: monosaccharides, disaccharides and polysaccharides with very high molecular weight.

The purpose of this research is to identify the meaning of pavement failure. Pavement failure are fatigue cracking, rutting, and thermal cracking. The first phase of this project we make some field word at our research road which is Jalan Universiti, Petaling Jaya. We also making literature review at Jabatan Kerja Raya (JKR) Library to get some information. The final phase we make an interview Assistant Engineer, Engineering Department Majlis Bandaraya Petaling Jaya (MBPJ). By identifying the pavement failure, we know the maintenance of MBPJ and the future plan of road.

Area Network (LAN) at Regional Office Surabaya Industrial and Trade Training Service. The object of study are employees which worked by LAN Service office and used primary datas non probability sampling with analysis factor throught SPSS 10,0 windows program. The corelation matrix result shows of variable population; Barlets test of Sphericity (BTS) 0,000 proved, and Kayser Meyer Oklin (KMO) 0,671 > 0,50 means sample strength enough. By rotation from 35 variables become 22 variables with cumulative percentation 64,67. Tools is the dominant factor impact of human computer interaction by Local Area Network (LAN). The contribution of variable 10,187%, with eigen values 3,573 consist of; tools by loading variable 0,813, language with loading variable 0,745 and on line by 0,661 variable loading.

To assess the sensitivity and specificity of previously described M mode echocardiographic signs of mitral valve prolapse, 100 subjects with a mobile mid systolic click and 100 matched normal control subjects were prospectively studied. Late systolic posterior motion and holosystolic hammocking of the mitral leaflets were common, highly specific signs of mitral valve prolapse. When these signs were combined as a single criterion, sensitivity was 85 percent and specificity was 99 percent. Other signs, including systolic echoes in the mid left atrium, systolic anterior motion, early diastolic anterior motion of the posterior mitral leaflet and shaggy or heavy cascading linear diastolic echoes posterior to the mitral valve, were highly specific but uncommon. They occurred only in combination with late systolic posterior motion or holosystolic hammocking. The remaining signs tested did not differentiate subjects with mitral valve prolapse from normal persons.