Technological features of repair cracks in ship plates by comb cutting method

Ремонт трещин в судовых пластинах является наиболее ответственной и сложной операцией Задача получения заданных размеров проплава с обратной стороны свариваемого металла резко усложняется в тех случаях, когда доступ к обратной стороне шва затруднен или вообще невозможен, выполнение двухсторонних сварных швов на наружной обшивке корпуса судна, в большинстве случаев для доступа к поврежденным районам, приводит к увеличению числа сопутствующих работ по демонтажу (монтажу) оборудования и влияет на нормативные сроки ремонта судов, в том числе и при стоянке судов в доке. В данной работе излагаются результаты исследования эффективности технологии ремонта трещин, в судовых пластинах, путем ориентации сварочной ванны вдоль плоскости повреждения, за счет гребенчатой разделки поврежденного района с различной геометрией кромок. Представлены результаты аналитического исследования и факторных экспериментов оценки прочности сварных соединений с различной геометрией гребенчатой разделки, при односторонней сварке, с использованием различных сварочных материалов и варьировании режимов сварки. Приведены результаты металлографического исследования (на макрошлифах) полученных сварных соединений. Предложены технологически эффективные, для практического применения в судоремонте, параметры гребенчатой разделки трещин в судовых пластинах. Repair of cracks in the ship plates is the most responsible and complex operation The task of obtaining the specified dimensions of the melt on the reverse side of the welded metal is sharply complicated in cases where access to the reverse side of the seam is difficult or even impossible, the implementation of double-sided welds on the outer skin of the hull of the vessel, in most cases for access to damaged areas, leads to an increase in the number of related works on the dismantling (installation) of equipment and affects the normative terms of repair of vessels, including when ships are parked in the dock. This paper presents the results of the study of the effectiveness of the technology of repair of cracks in the ship plates, by orienting the welding bath along the damage plane, due to the comb cutting of the damaged area with different geometry of the edges. The results of analytical research and factor experiments assessment of the strength of welded joints with different geometry of comb cutting, with one-sided welding, using different welding materials and varying welding modes. The results of metallographic research (on macro-grinds) of the obtained welded joints are given. Technologically effective parameters of comb cutting of cracks in ship plates are proposed for practical application in ship repair.

FORMULASI SEDIAAN LOTION SEBAGAI TABIR SURYA DARI EKSTRAK METANOL KULIT LUAR BUAH JENGKOL (Archidendron jiringa (jack) I.C.Nielsen)

Sunscreen is a chemical or ingredient that contains elements that protect the skin from the harmful effects of direct sunlight. The flavonoid molecules in the jengkol fruit's outer skin have a conjugated aromatic benzene group, which can absorb UVA or UVB radiation and cause skin damage. The goal of this study is to figure out what concentration of methanol extract of the outer skin of jengkol fruit (100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm) gives the best SPF value and what effect that concentration has on the outer skin of jengkol fruit as an active ingredient in sunscreen preparations. Using spectrophotometry, the efficacy of a methanol extract of the outer skin of the jengkol fruit as an active component in sunscreen was assessed at concentrations of 100 ppm, 150 ppm, 200 ppm, 250 ppm, and 300 ppm. The methanol extract of the jengkol fruit's outer peel had a concentration of 300 ppm (SPF value 4.783) and was divided into three formulae with concentrations of 0.3 (F1), 0.45 (F2), and 0.65 (F3) (F3). Physical, chemical, stability, and SPF quality of the resulting formulations were evaluated. Each jengkol fruit outer skin extract lotion formulation was shown to be effective as a sunscreen, with SPF values of 27.90 (F1), 8.46 (F2), and 15.56 respectively (F3)ABSTRAKTabir surya adalah zat atau ramuan yang mengandung bahan kandungan pelindung kulit terhadap paparan sinar matahari langsung yang dapat menyebabkan gangguan kulit. Senyawa flavonoid dalam kulit luar buah jengkol memiliki gugus benzene aromatic terkonjugasi yang dapat menyerap sinar UVA atau UVB serta dapat menyebabkan efek buruk terhadap kulit. Penelitian ini bertujuan untuk menentukan konsentrasi ekstrak methanol kulit luar buah jengkol (100 ppm, 150 ppm, 200 ppm, 250 ppm, 300 ppm) yang memberikan nilai SPF paling baik dan mengetahui pengaruh konsentrasi ekstrak metanol kulit luar buah jengkol sebagai bahan aktif sediaan tabir surya. Ekstrak metanol kulit luar buah jengkol dengan menggunakan konsentrasi 100 ppm, 150 ppm, 200 ppm, 250 ppm, dan 300 ppm yang ditentukan efektivitasnya sebagai bahan aktif tabir surya menggunakan spektrofotometri. Ekstrak metanol kulit luar buah jengkol dengan konsentrasi 300 ppm (nilai SPF 4,783) diformulasikan dalam tiga formula dengan variasi konsentrasi 0,3 (F1), 0,45 (F2), 0,65 (F3). Sediaan yang diperoleh dievaluasi mutu fisik, kimia, stabilitas, dan SPF. Masingmasing formula lotion ekstrak kulit luar buah jengkol ditentukan efektifitasnya sebagai tabir surya dan mendapatkan nilai SPF 27,90 (F1), 8,46 (F2) dan 15,56 (F3).

Verification of a chamberless HLFC design with an outer skin of variable porosity

A chamberless HLFC leading edge segment featuring an outer skin with variable porosity has been designed, manufactured and wind tunnel tested under flight Reynolds-number conditions. The aerodynamic design involved the extention of current HLFC design routines to variable pressure loss characteristics of the outer skin. Advanced options for structural design and manufacturing solutions with focus on industrialization, arising from the avoidance of aerodynamically driven chambering, are explored. The leading edge segment has been installed on an existing vertical tail-plane model and tested at the large low-speed wind-tunnel facility DNW-LLF. The design process and some results of the successful verification of the chamberless design are presented herein.

Temporomandibular joint and Giant Panda’s (Ailuropoda melanoleuca) adaptation to bamboo diet

Here, we present new evidence that evolutionary adaptation of the Ailuripodinae lineage to bamboo diet has taken place by morphological adaptations in the masticatory system. The giant panda in the wild and in captivity removes without an exception the outer skin of all bamboo shoots, rich in abrasive and toxic compounds, by the highly adapted premolars P3 and P4. The temporomandibular joint (TMJ) allows sidewise movement of the jaw and the premolars can, in a cusp-to-cusp position, remove the poorly digestible outer skin of the bamboo before crushing the bamboo with molars. Based on the evidence presented here, we suggest that adaptation of TMJ to lateral movement for enabling cusp-to-cusp contact of premolars is the crucial evolutionary factor as which we consider the key to understand the Ailuropodinae lineage adaptive pathway to utilize the bamboo resource.

All About Cells

This chapter takes the reader on an imaginary scuba diving tour of the watery world of the cell and its surroundings, pointing out features such as the cytoskeleton (that forms the equivalent of the bones and muscles of our cells), the cell membrane (the outer skin of the cell), and the cell membrane’s embedded proteins that provide selective access to the interior of the cell—organelles (elfin versions our own organs). The chapter stresses the tumultuous action that occurs non-stop within the cells as proteins are assembled for use within and outside the cells. The chapter discusses stem cells, including the discovery of induced pluripotent stem cells. The chapter relates how cells differentiate to become dissimilar cell types, stresses the importance of three-dimensional study of cells (rather than two-dimensional study), and explains the different ways in which cells talk to each other.

Structural performance of a climbing cactus: making the most of softness

Climbing plants must reach supports and navigate gaps to colonize trees. This requires a structural organization ensuring the rigidity of so-called ‘searcher’ stems. Cacti have succulent stems adapted for water storage in dry habitats. We investigate how a climbing cactus Selenicereus setaceus develops its stem structure and succulent tissues for climbing. We applied a ‘wide scale’ approach combining field-based bending, tensile and swellability tests with fine-scale rheological, compression and anatomical analyses in laboratory conditions. Gap-spanning ‘searcher’ stems rely significantly on the soft cortex and outer skin of the stem for rigidity in bending (60–94%). A woody core contributes significantly to axial and radial compressive strength (80%). Rheological tests indicated that storage moduli were consistently higher than loss moduli indicating that the mucilaginous cortical tissue behaved like a viscoelastic solid with properties similar to physical or chemical hydrogels. Rheological and compression properties of the soft tissue changed from young to old stages. The hydrogel–skin composite is a multi-functional structure contributing to rigidity in searcher stems but also imparting compliance and benign failure in environmental situations when stems must fail. Soft tissue composites changing in function via changes in development and turgescence have a great potential for exploring candidate materials for technical applications.

NILAI TAMBAH DAN KELAYAKAN PENGOLAHAN AREN MENJADI KOLANG KALING

Penelitian ini bertujuan untuk mengetahui proses pengolahan aren menjadi kolang kaling, untuk mengetahui nilai tambah yang dihasilkan dari pengolahan aren menjadi kolang kaling, untuk menganalisis pendapatan pengolahan aren menjadi kolang kaling, untuk menganalisis tingkat kelayakan usaha pengolahan aren menjadi kolang kaling. Penentuan daerah penelitian dilakukan secara purposive atau sengaja. Pengambilan sampel penelitian menggunakan metode sensus, dengan sampel penelitian sebanyak 21 orang.Pada hasil penelitian diperoleh tahapan pengolahan aren menjadi kolang kaling terdiri dari 6 tahapan yaitu, 1. penyediaan bahan baku, 2. pemilihan aren, 3. pengupasan kulit luar dengan cara merebus, 4. pengambilan kolang kaling, 5. perendaman kolang kaling, 6. pemipihan kolang kaling.Biaya produksi pengolahan aren menjadi kolang kaling sebesar Rp 958.637,57, penerimaan pengolahan aren menjadi kolang kaling sebesar Rp 2.400.000, pendapatan pengolahanaren menjadi kolang kaling sebesar Rp 1.441.362,44 per bulan.. Nilai tambah yang dihasilkan dari pengolahan aren menjadi kolang kaling tergolong tinggi dengan ratio nilai tambah sebesar 61,96 % atau ≥ 50%. Kelayakan usaha pengolahan aren menjadi kolang kaling di daerah penelitian layak untuk diusahakan,ini terlihat dengan nilai R/C rasio sebesar 2,50 > 1, BEP produksi adalah sebesar 239,66 (produksi > BEP Produksi yaitu 600,00 kg > 239,66 kg) dan BEP harga yaitu sebesar Rp 4.000,00 (harga jual > BEP Harga yaitu Rp 4.000 > Rp 1.597,72) This study aims to determine the processing of palm sugar into kolang kaling, to determine the added value generated from processing palm sugar into kolang kaling, to analyze the income from processing sugar palm into kolang kaling, to analyze the feasibility of processing sugar palm into kolang kaling. The research area was determined purposively or deliberately. The research sample was taken using the census method, with a research sample of 21 people. The results showed that the stages of processing palm sugar into kolang kaling consisted of 6 stages, namely, 1. supply of raw materials, 2. selecting palm, 3. peeling the outer skin by boiling, 4. taking kolang kaling, 5. soaking kolang kaling, 6. flaking and fro. The production cost of processing palm sugar into kolang kaling is Rp. 958,637.57, revenue processing sugar into kolang kaling is Rp. 2,400,000. 1,441,362.44 per month .. The added value generated from processing palm sugar into kolang kaling is classified as high with an added value ratio of 61.96% or ≥ 50%. The feasibility of processing sugar palm into a palm fruit in the research area is feasible, this can be seen by the R / C ratio value of 2.50> 1, the BEP for production is 239.66 (production> BEP Production is 600.00 kg> 239.66. kg) and the BEP price is IDR 4,000.00 (selling price> BEP price is IDR 4,000> IDR 1,597.72).