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Current regimen to treat patients suffering from stress urinary incontinence often seems not to yield satisfactory improvement or may come with severe side effects. To overcome these hurdles, preclinical studies and clinical feasibility studies explored the potential of cell therapies successfully and raised high hopes for better outcome. However, other studies were rather disappointing. We therefore developed a novel cell injection technology to deliver viable cells in the urethral sphincter complex by waterjet instead of using injection needles. We hypothesized that the risk of tissue injury and loss of cells could be reduced by a needle-free injection technology. Muscle-derived cells were obtained from young male piglets and characterized. Upon expansion and fluorescent labeling, cells were injected into cadaveric tissue samples by either waterjet or injection needle. In other experiments, labeled cells were injected by waterjet in the urethra of living pigs and incubated for up to 7 days of follow-up. The analyses documented that the cells injected by waterjet in vitro were viable and proliferated well. Upon injection in live animals, cells appeared undamaged, showed defined cellular somata with distinct nuclei, and contained intact chromosomal DNA. Most importantly, by in vivo waterjet injections, a significantly wider cell distribution was observed when compared with needle injections (P <.05, n ≥ 12 samples). The success rates of waterjet cell application in living animals were significantly higher (≥95%, n = 24) when compared with needle injections, and the injection depth of cells in the urethra could be adapted to the need by adjusting waterjet pressures. We conclude that the novel waterjet technology injects viable muscle cells in tissues at distinct and predetermined depth depending on the injection pressure employed. After waterjet injection, loss of cells by full penetration or injury of the tissue targeted was reduced significantly in comparison with our previous studies employing needle injections. [ABSTRACT FROM AUTHOR]

Oil shale is one of the most promising replacements for traditional energy resources. Its total reserves are enormous, and, moreover, they are widespread. This makes shale oil insensitive to problems of individual suppliers. A lot of countries, which lack traditional energy sources for their development, are conducting investigations in the field of an increase of the effectiveness of oil shale as a substitute for oil and gas. These studies are mostly concerned with processing of oil shale. At this, economic and ecological effects could also be reached upon extraction. This paper deals with experimental studies on cutting oil shale by high-pressure water jets. The outcome was establishing a generalized equation for calculating the efficiency of oil shale cutting by high-pressure water jets and equations for estimating rational values of hydraulic parameters such as water pressure and diameter of the nozzle orifice as well as rational value of the traverse speed. [ABSTRACT FROM AUTHOR]

This work evaluates the possibility of identifying mechanical parameters, especially upper and lower yield points, by the analytical processing of specific elements of the topography of surfaces generated with abrasive waterjet technology. We developed a new system of equations, which are connected with each other in such a way that the result of a calculation is a comprehensive mathematical-physical model, which describes numerically as well as graphically the deformation process of material cutting using an abrasive waterjet. The results of our model have been successfully checked against those obtained by means of a tensile test. The main prospect for future applications of the method presented in this article concerns the identification of mechanical parameters associated with the prediction of material behavior. The findings of this study can contribute to a more detailed understanding of the relationships: material properties--tool properties--deformation properties. [ABSTRACT FROM AUTHOR]

Farklı alanlarda yaygın kullanım olanağı bulan su jeti teknolojisi; düşük kesme kuvveti gerektirmesi, esnek ve çok yönlü kesme olanağına sahip olması nedeniyle geleneksel kesme sistemlerine alternatif bir yöntem olarak kullanılmaktadır. Madencilik alanında ilk olarak yumuşak kayaçların kazılması işleminde kullanılan su jeti teknolojisi, kömürün hidrolik kazılabilirliği ile bu alandaki kullanımını arttırmıştır. Günümüzde ise doğal taş ocak işletmeciliğinde blok kesimi ve doğal taş işleme süreçlerinde dekoratif üretim amaçları için yaygın olarak kullanılmaktadır. Yöntem delik delme ve tünel açma işlemlerinde de kullanım olanağı bulmuştur. Son yıllarda, su jeti teknolojisinin boyut küçültme işlemlerinde kullanımını yaygınlaştırmak için araştırmalar yapılmaktadır. Bu çalışmada, su jeti teknolojisinin madencilik sektöründeki bazı kullanım alanlarına yönelik bir değerlendirme sunulmuştur. Ek olarak su jeti teknolojisinin madencilikte kullanılan diğer kesme sistemlerine göre çeşitli açılardan karşılaştırılması da yapılmıştır. Çalışma sonucunda, su jeti teknolojisi ile yapılan kesme işleminde malzeme kaybının az olması, kesim sonrası ikincil işlem gerektirmemesi, toz problemini ortadan kaldırması, kayaç veya kömür parçalanma veriminin artması ve aşınma kaynaklı maliyetlerin azaltılması gibi avantajları nedeniyle madencilik sektöründe verimli bir şekilde kullanılabileceği tespit edilmiştir.

Farklı alanlarda yaygın kullanım olanağı bulan su jeti teknolojisi; düşük kesme kuvveti gerektirmesi, esnek ve çok yönlü kesme olanağına sahip olması nedeniyle geleneksel kesme sistemlerine alternatif bir yöntem olarak kullanılmaktadır. Madencilik alanında ilk olarak yumuşak kayaçların kazılması işleminde kullanılan su jeti teknolojisi, kömürün hidrolik kazılabilirliği ile bu alandaki kullanımını arttırmıştır. Günümüzde ise doğal taş ocak işletmeciliğinde blok kesimi ve doğal taş işleme süreçlerinde dekoratif üretim amaçları için yaygın olarak kullanılmaktadır. Yöntem delik delme ve tünel açma işlemlerinde de kullanım olanağı bulmuştur. Son yıllarda, su jeti teknolojisinin boyut küçültme işlemlerinde kullanımını yaygınlaştırmak için araştırmalar yapılmaktadır. Bu çalışmada, su jeti teknolojisinin madencilik sektöründeki bazı kullanım alanlarına yönelik bir değerlendirme sunulmuştur. Ek olarak su jeti teknolojisinin madencilikte kullanılan diğer kesme sistemlerine göre çeşitli açılardan karşılaştırılması da yapılmıştır. Çalışma sonucunda, su jeti teknolojisi ile yapılan kesme işleminde malzeme kaybının az olması, kesim sonrası ikincil işlem gerektirmemesi, toz problemini ortadan kaldırması, kayaç veya kömür parçalanma veriminin artması ve aşınma kaynaklı maliyetlerin azaltılması gibi avantajları nedeniyle madencilik sektöründe verimli bir şekilde kullanılabileceği tespit edilmiştir.

Under the support of an SBIR Phase II/IIB grant from the National Science Foundation, OMAX has developed and commercialized micro abrasive (µAWJ), culminating A MicroMAX® JetMachining® Center technology for meso-micro machining. AWJ inherently possesses technological and manufacturing merits unmatched by most machine tools. With the commercialization of µAWJ technology, waterjet is now fully capable of multi-mode machining most materials from macro to micro scales (the 7M advantage). Novel accessories and software facilitate machining precision 2D and 3D parts with a wide range of part size and thickness. The versatile waterjet is particularly advantageous for machining difficult and delicate materials, such as alloys, hardened steel, composites, and laminates. One unique capability is machining composites and nanomaterials comprised of metals (reflective and conductive), non-metals (non-conductive), and anything in between. The 7M advantage of waterjet has been taking advantage by machining sample parts made of a variety of advanced materials that are difficult, or even impossible, to machine otherwise.

Waterjet technology finding broad application potential in different areas, due to having low cutting force required and the possibility of flexible and multi-directional cutting, is used as an alternative method over the conventional cutting systems. Waterjet technology, used firstly in excavation processes of soft rocks in mining, has increased its usability with the hydraulic excavation of coal. Nowadays, it is commonly used for block cutting in quarries and processing of natural stones for the purposes of decorative production. The method has the potential use in drilling and tunneling processes too. Recently, investigations have been carried out to enhance the usability of the technology in milling processes. In this study, an assessment of some applications of waterjet technology in mining is presented. Additionally, the technology is compared with other cutting systems used in mining in terms of various aspects as well. As a result of the study, it is determined that the cutting process with waterjet technology could be efficiently used in mining sector because of the advantages such as little material losses, not requiring any additional processes after cutting, eliminating the dust, increasing the fragmentation efficiency of rock or coal, decreasing the costs resulted from wear. [ABSTRACT FROM AUTHOR]

The present study is focused on the surface roughness of abrasive waterjet (AWJ) cut surfaces. This study explains the effects of feed rate and thickness of workpiece on the roughness. Considering experimental data, effects of the composition of the material on surface roughness are assessed. The study also evaluates the deformation effect of AWJ on workpieces that have the same composition but different thickness. In the study pure aluminium, Al-6061 aluminium alloy, brass-353 (α+β brass), AISI 1030 and AISI 304 steel materials are cut with AWJ at different feed rates. Improvement in surface roughness of pure aluminium remains in narrow limited range when compared with the ratio of decrease in feed rate. Experimental results explain “cutting wear” and “deformation wear” mechanisms are effective in cutting both of the mild and the brittle structure materials with AWJ. The pressure of the AWJ negatively affects the surface roughness as the thickness of the material decreases. Brass and AISI 1030 materials that have higher strength than aluminium result in higher surface roughness for thinner workpieces. Reducing feed rate from 25 to 20 mm/min deteriorated the surface properties of 20 mm thickness workpiece of AISI 304, in contrast to all of the other studied 20 mm thickness materials. Additional studies are required to understand this different behaviour of 20 mm thickness specimen of AISI 304. [Copyright &y& Elsevier]

The article focuses on the machining of polymeric materials polypropylene (PP) and un-plasticized poly vinyl chloride (PVC-U) after surface treatment with polyurethane and acrylate coatings using waterjet technology. Two types of waterjet technologies, abrasive waterjet (AWJ) and waterjet without abrasive (WJ), were used. The kerf width and its taper angle, at the inlet and outlet of the waterjet from the workpiece, were evaluated. Significant differences between AWJ and WJ technology were found. WJ technology proved to be less effective due to the creation of a nonuniform cutting gap and significant burrs. AWJ technology was shown to be more efficient, i.e., more uniform cuts were achieved compared to WJ technology, especially at a cutting head traverse speed of 50 mm·min−1. The most uniform kerf width or taper angle was achieved for PP + MOBIHEL (0.09°). The materials (PP and PVC-U) with the POLURAN coating had higher values of the taper angle of the cutting gap than the material with the MOBIHEL coating at all cutting head traverse speeds. The SEM results showed that the inappropriate cutting head traverse speed and the associated WJ technology resulted in significant destruction of the material to be cut on the underside of the cut. Delamination of the POLURAN and MOBIHEL coatings from the base material PP and PVC-U was not demonstrated by SEM analysis over the range of cutting head traverse speeds, i.e., 50 to 1000 mm·min−1. [ABSTRACT FROM AUTHOR]