Final report of grit blasting and metal spraying trials carried out at H. M. Dockyard, Devonport

Mild steel surfaces that are to be protected by aluminium or zinc spray coatings are generally prepared by blasting with chilled iron angular grit. Previous work1had shown that a relationship exists between the grit blasting conditions (at least in terms of blasting angle and grit condition), the reflectivity of the blasted surface and the bond strength of a spray coating of aluminium on the blasted surface. An instrument has been developed that assesses the suitability of a blasted surface for subsequent spraying by measuring the reflectivity and has proved reasonably successful under laboratory conditions. The present need is to ascertain the performance of this reflectivity meter under shop and site conditions. The opportunity to carry out such tests at H.M. Dockyard, Devonport, was offered by the Ministry of Defence and a series of tests was made on 16th June, 1965

Method and apparatus for gripping uniaxial fibrous composite materials

A strip specimen is cut from a unidirectional strong, brittle fiber composite material, and the surfaces of both ends of the specimen are grit blasted. The specimen is then placed between metal load transfer members having grit blasted surfaces. Sufficient compressive stress is applied to the load transfer members to prevent slippage during testing at both elevated temperatures and room temperatures. The need for adhesives, load pads, and other secondary composite processing is eliminated. This gripping system was successful in tensile testing, creep rupture testing, and fatigue testing uniaxial composite materials at 316 C

Effect of surface finishing such as sand-blasting and CrAlN hard coatings on the cutting edge’s peeling tools’ wear resistance

The authors would like to thank IonBond (Chassieu-France) who made the sand-blasting treatments and the Regional Council of Burgundy and CTBA (Wood and Furniture Technical Centre) for their financial support.The aim of this study is first to define the effect of a surface finishing such as sand-blasting on the geometry of a wood cutting tool and its wear resistance. In addition, the effectiveness of surface coatings like CrAlN deposited by physical vapor deposition (PVD) technique on conventional and sand-blasted cutting edges was studied. A reference tool and different sand-blasted ones were tested by micro-peeling of beech in a laboratory. Microscopic observations, cutting forces measurement and cutting wear tests were carried out to quantify the behavior of these tools. The results obtained showed that the artificial wear by sandblasting leads to an increase in the wear resistance and coating effectiveness, and completely changes the type of damage done to the tools. The sand-blasting application combined or not with CrAlN coating showed an improvement in the wear resistance of the tools and a modification of the forces during the peeling process. The effectiveness of the CrAlN layers was improved thanks to the sand-blasting treatment and then the duplex ones performed better.Regional Council of Burgundy CTBA (Wood and Furniture Technical Centre

Improvment of safety conditions of unstable rock slopes through the use of explosives

The paper discusses operations aimed at creating a safer natural or man made rock slope by artificially inducing the displacement of unstable elements by blasting. A detailed analysis of the problems with the use of explosives present when conducting these activities is carried out focusing on the advantages and disadvantages of this technology. The results of two examples of demolition of instable rock elements are presented and discussed thus providing suggestions for future blasting design

The unburiable: Representations of pain and violence in selected works of Sarah Kane and Caryl Churchill

In this thesis I intend to answer the question of how representations of pain and violence in the selected plays of Kane and Churchill assist the critical understanding of those works. The works I have selected are Sarah Kane’s Blasted and Caryl Churchill’s Seven Jewish Children: A play for Gaza. To assist the understanding of the spectator and to enable me to engage with the plays in closer detail I draw on a selection of theories from the philosophers Judith Butler and Arne Johan Vetlesen. In particular I discuss Butler’s theorisation of grief, vulnerability and responsibility to (and for) the Other. I also discuss Vetlesen’s responses to pain and torture, with emphasis on his notions of pain transference. From my reading and analysis of the plays, I find that both works provoke a complex set of responses to issues of communal responsibility and identity. The reference in the title to ‘the unburiable’ is a term coined by Butler to explain the efforts of some people to dehumanise the Other. Applying the theoretical ideas of Butler and Vetlesen to the plays provides a way to negotiate the fragile gap between those that matter and those who have become the unburiable

Probabilistic Model Counting with Short XORs

The idea of counting the number of satisfying truth assignments (models) of a formula by adding random parity constraints can be traced back to the seminal work of Valiant and Vazirani, showing that NP is as easy as detecting unique solutions. While theoretically sound, the random parity constraints in that construction have the following drawback: each constraint, on average, involves half of all variables. As a result, the branching factor associated with searching for models that also satisfy the parity constraints quickly gets out of hand. In this work we prove that one can work with much shorter parity constraints and still get rigorous mathematical guarantees, especially when the number of models is large so that many constraints need to be added. Our work is based on the realization that the essential feature for random systems of parity constraints to be useful in probabilistic model counting is that the geometry of their set of solutions resembles an error-correcting code.Comment: To appear in SAT 1

Beneficial Effect of Pt and of Pre-Oxidation on the Oxidation Behaviour of an NiCoCrAlYTa Bond-Coating for Thermal Barrier Coating Systems

The oxidation behaviour of a thermal barrier coating (TBC) system is a major concern as the growth of the thermally grown oxide (TGO) layer on the bondcoating creates stresses that greatly favour the thermal barrier spallation. To delay the loss of the thermal protection provided, research has focused on the bondcoating composition and microstructure as well as on the parameters required for a suitable pre-oxidation treatment before the deposition of the ceramic top coat. Platinum is known to enhance the oxidation/corrosion resistance of MCrAlY coatings. The effect of Pt on the oxidation behaviour of a NiCoCrAlYTa coating was assessed in this study. In addition, pre-oxidation treatments were conducted to determine if the oxidation behaviour of the modified NiCoCrAlYTa coating could be further improved

Evaluation of blasting in an opencast mine

Fragmentation is one of the key issues in opencast blasting as properties like shape and size of rock materials are very important information for production optimization. The degree of fragmentation influences the economy of the mining process and hence the fragmentation of blasted rock forms the basis to evaluate the quality of a blast. Digital image processing technique is the latest fragmentation analysis tool. This technique has recently been proved better than the conventional methods. Those methods are also time saving and offer accurate measurement. Wipfrag is an image analysis system for measuring size distribution for blasted or crushed rock. It was developed by Wipware, Inc. Canada. It accepts images from a variety of sources such as roving cam coders, digital camera, photographs, or digital files. It uses automatic algorithms to identify individual fragments on the image, and measures the profile areas on the blocks. It reconstructs a three-dimensional distribution using geometric probability. In this study, 10 images from a blasted chromite muck pile were analysed through WipFrag image analysis system. Both single and merged image analysis were done and the merged image analysis was used to evaluate optimum fragmentation. Mean fragmented size of the blasted rocks has been predicted from the analysis

Intensification of technological processes in drilling and blasting operations during open-cut mining in Kyzylkum region

Purpose. It is found that for long term standing, the pit bench profile is close to the boundary of the disturbed zone. Therefore, long stability of the bench can be estimated in respect to the size of the disturbed area and the boundary of residual deformations zone. Methods. Protective ability of the shielding splitting during the perimeter blasting in Kyzylkum quarries is estimated by the amplitude coefficient depending on the width of the shielding splitting, duration of explosive pulse as well as physical and mechanical properties of the shielding splitting filler. Findings. Analysis of the research regarding special methods of conducting drilling and blasting operations (DBO) for bench slope development showed that the most effective way of reducing deformation zone beyond the designed surface of separation is to use pre-splitting. Analysis of the research related to selecting parameters of contouring charges for creating a shielding splitting revealed the absence of methods which can reasonably and unequivocally recommend DBO parameters for specific mining and geological conditions. Currently known dependences only approximately allow to estimate the relationships between the main parameters of contouring explosives. Originality. In accordance with the “Research method of blast impact of contouring charges in the border zone of the quarry”, experiential and industrial tests of the developed blast design and effective parameters of perimeter blasting have been conducted in Muruntau quarry. As a result, stable slopes of 20-meter benches with the slope angle 60 degrees were formed, eliminating the need for additional wall cutback, simultaneously improving labour safety at lower horizons. The developed effective parameters of perimeter blasting ensured creation of maximal widest shiel-ding splitting for the designed limit of the disturbance zone thickness with destroyed inter-block connections in the area adjacent to the slope. Practical implications. Fixing mixture underwent industrial testing and was implemented in Tashkura quarry of Djeroy-Sardara phosphorite fields. It was established that during explosive fragmentation of rock mass, using stemming of fixing mixture, the amount of dust and gas clouds is reduced by 30 – 35% as compared with stems made of drill cuttings.Мета. Розробка і впровадження способів інтенсифікації процесів буропідривних робіт на кар’єрах Кизилкумського регіону, що дозволяють забезпечити необхідну якість підірваної гірничої маси, можливість управління формою та параметрами розвалу, збереження геологічної структури масиву й скорочення часу підготовчо-відновлювальних робіт. Методика. Кількісна оцінка ефекту від застосування методу попереднього щілеутворення на кар’єрах Кизилкумського регіону оцінена за допомогою коефіцієнта ефективності застосування контурного підривання, а захисна здатність екрану щілини при контурному підриванні – амплітудним коефіцієнтом, що залежить від ширини екрану щілини, тривалості вибухового імпульсу та фізико-механічних властивостей заповнювача щілини. Результати. В результаті проведених теоретичних досліджень отримано залежності для визначення ефективних параметрів контурного підривання з умови сумісності вимоги проростання мережі тріщин між оконтурюючими свердловинами. Захисна здатність екрану щілини істотно залежить від щільності її заповнювача, тому при розрахунку параметрів контурних зарядів необхідно враховувати розкриття відрізної щілини за рахунок ущільнення прилеглого масиву. Параметри оконтурюючих зарядів повинні вибиратися з урахуванням обмеження зони порушення міжблочних зав’язків відповідно до вимог забезпечення стійкості укосів уступів. Наукова новизна. Встановлено, що при довготривалому стоянні профіль уступу наближається до профілю межі зони порушень, що дозволяє судити про тривалу стійкість уступу. Розроблено математичну модель, що описує дію вибуху свердловинного заряду вибухової речовини в масиві, на основі якої визначено кінематичні параметри розльоту гірських порід. Практична значимість. Розроблені ефективні параметри контурного підривання забезпечують створення максимально широкої екрануючої щілини при заданому обмеженні потужності зони порушень міжблочних зв’язків у приукісній частині масиву. При вибуховому розпушуванні гірського масиву з використанням забійки із закріплюючої суміші обсяг пилогазової хмари зменшується на 30 – 35% у порівнянні з розпушуванням із використанням забійки з бурового дрібняку. Закріплююча суміш впроваджена на кар’єрі Ташкура Джерой-Сардарінського родовища фосфоритів.Цель. Разработка и внедрение способов интенсификации процессов буровзрывных работ на карьерах Кызылкумского региона, позволяющих обеспечить необходимое качество взорванной горной массы, возможность управления формой и параметрами развала, сохранение геологической структуры массива и сокращение времени подготовительно-восстановительных работ. Методика. Количественная оценка эффекта от применения метода предварительного щелеобразования на карьерах Кызылкумского региона оценена с помощью коэффициента эффективности применения контурного взрывания, а защитная способность экранирующей щели при контурном взрывании – амплитудным коэффициентом, зависящим от ширины экранирующей щели, длительности взрывного импульса и физико-механических свойств заполнителя щели. Результаты. В результате проведенных теоретических исследований получены зависимости для определения эффективных параметров контурного взрывания из условия совместимости требования прорастания сети трещин между оконтуривающими скважинами. Защитная способность экранирующей щели существенно зависит от плотности ее заполнителя, поэтому при расчете параметров оконтуривающих зарядов необходимо учитывать раскрытие отрезной щели за счет уплотнения прилегающего массива. Параметры оконтуривающих зарядов должны выбираться с учетом ограничения зоны нарушения межблочных связей в соответствии с требованиями обеспечения устойчивости откосов уступов. Научная новизна. Установлено, что при долговременном стоянии профиль уступа приближается к профилю границы зоны нарушений, что позволяет судить о длительной устойчивости уступа. Разработана математическая модель, описывающая действие взрыва скважинного заряда взрывного вещества в массиве, на основе которой определены кинематические параметры разлета горных пород. Практическая значимость. Разработанные эффективные параметры контурного взрывания обеспечивают создание максимально широкой экранирующей щели при заданном ограничении мощности зоны нарушений межблочных связей в приоткосной части массива. При взрывном рыхлении горного массива с использованием забойки из закрепляющей смеси объем пылегазового облака уменьшается на 30 – 35% по сравнению с рыхлением с использованием забойки из буровой мелочи. Закрепляющая смесь внедрена на карьере Ташкура Джерой-Сардаринского месторождения фосфоритов.The paper did not originate under any project and no funding was raised

Interleukin-10 containing normal human serum inhibits granzyme B release but not perforin release from alloreactive and EBV-specific T cell clones

Interleukin-10 (IL-10), also known as cytokine synthesis inhibitory factor, has pleiotropic effects in immunoregulation and inflammation. It is capable of inhibiting synthesis of pro-inflammatory cytokines like interferon γ (IFNγ), IL-2, IL-3, tumor necrosis factor α(TNFα) and granulocyte macrophage colony stimulating factor (GM-CSF) made by cells such as macrophages and T helper Type 1 cells. We observed that normal human serum, derived from a healthy individual but containing large amounts of IL-10 (arbitrarily designated as "IL-10 serum"), inhibited cytotoxic activity and interfered with granzyme B release from alloreactive cytotoxic T cell (CTL) clones _in vitro_, but did not affect perforin release. The addition of normal human serum containing high levels of anti-IL-10 IgG (arbitrarily designated as "anti-IL-10 IgG serum") neutralized the inhibitory effects of IL-10 serum. Moreover, we have identified that cytotoxic activity and granzyme B release from an Epstein-Barr virus (EBV)-specific CTL clone was similarly inhibited in the presence of IL-10 serum, while perforin release was unaffected. Anti-IL-10 IgG serum also appeared to neutralize the inhibitory effect of IL-10 serum on an EBV-specific CTL clone