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INSTRUMENTATION OF OPERATIONAL BOMBER AIRCRAFTAbbott, Laird 10 1900 (has links)
International Telemetering Conference Proceedings / October 26-29, 1998 / Town & Country Resort Hotel and Convention Center, San Diego, California / Airborne instrumentation used during flight tests is being installed and maintained in a
unique way by operational bomber testers from the Air Force’s 53d Wing. The ability of
the flight test community to test on operational aircraft has always been somewhat
curtailed by the need for advanced forms of instrumentation. Operational fighter flight
test squadrons have aircraft assigned to them, which they modify on as needed basis,
much the same as developmental testers. However, bomber operational test units must
use operational aircraft to accomplish their mission as there are no bombers in the Air
Force’s Air Combat Command (ACC) specifically set aside for operational tests. During
test missions, these units borrow aircraft from operational bomb wings, and then return
them to service with the bomb wing after testing is complete. Yet, the requirement for
instrumentation on these test missions is not much different than that of developmental
testers. The weapon system engineer’s typically require Mil-Std-1553, video, telemetry,
and Global Positioning System (GPS) Time-Space-Position-Information airborne
receiver recordings. In addition, this data must be synchronized with an IRIG-B time
code source, and recorded with the same precision as the data gathered during
development test and evaluation (DT&E). As a result, several techniques have been
developed, and instrumentation systems designed for these operational test units to
incorporate instrumentation on operational aircraft.
Several factors hamper the usual modification process in place at bases such as Edwards
AFB and Eglin AFB. Primary among these is the requirement to maintain the aircraft in
an operational configuration, and still meet all of the modification design safety criteria
placed on the design team by the aircraft’s single manager. Secondary to the list of
restrictions is modification time. Aircraft resources are stretched quite thin when one
considers all of the bomb wing’s operational commitments. When they must release an
aircraft for test missions, the testers must insure that schedule impacts are minimal.
Therefore, these systems must install and de-install within one to two days and be
completely portable. Placing holes in existing structures or adding new permanent
structure is unacceptable. In addition, these aircraft must be capable of returning to
combat ready status at any time. This paper centers on the B-52 bomber, and the active aircraft temporary modifications
under control of the 49th Test Squadron (49 TESTS) at Barksdale AFB in Louisiana. The
B-52 presents unique design challenges all its own, in addition to the general restrictions
already mentioned. This paper will present the options that the 49 TESTS has
successfully used to overcome the aforementioned restrictions, and provide an
appropriate level of specialized instrumentation for its data collection requirements.
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The impact of HLA-driven escape mutation on viral replicative capacity and immune control in HIV infectionTsai, Ming-Han Chloe January 2017 (has links)
Despite the introduction of antiretroviral therapy, the HIV/HIV epidemic remains an unsolved global health problem. Amongst all the host defence mechanisms, HLA class I molecules have shown the strongest genetic association with delayed disease progression, in particular HLA-B alleles. Numerous studies have shown that the HLAmediated CD8+ T cell responses play a central role in the immune control of HIV. Yet our understanding of HLA-mediated immune control of HIV remains incomplete, even when considering the best-defined epitopes restricted by the protective HLA alleles at a population level. The studies I have conducted and describe herein focus on two well-charaterised protective HLA-B molecules, HLA-B*81:01 and HLA-B*27:05; a third protective molecule, HLA-B*52:01, that has not been well-studied hitherto; and finally the most prevalent HLAB allele in many Asian populations such as Taiwan, HLA-B*40:01, which has an apparently neutral effect on viral replication. This thesis is centred on the Gag-specific immune response, since previous studies have shown the benefits of CD8+ T-cell responses targeting this conserved and immunogenic region of the HIV proteome, in particular the p24 capsid protein. I have investigated here HLA footprints driven by CD8+ T-cell pressure on HIV that are evident in the viral sequences of individuals expressing these HLA molecules. These footprints include novel escape and putative compensatory mutations. The impact of these variants on viral replicative capacity (VRC) and on HIV disease outcome clinical outcomes was examined via fitness assays. These studies identified several escape mutations that effectively cripple HIV. The distinct compensatory pathways available to the virus to mitigate the fitness cost of particular escape mutations were evaluated. In the course of these analyses I have demonstrated the critical influence of the viral backbone, including HIV clade, in combination with particular viral variants, on VRC. Computational modelling analysis has been applied to facilitate understanding of the mechanism by which certain mutants affect the stability of interactions between HLA and viral capsid protein. This thesis offers novel insights into immune control of the key HIV subtypes â B- and C-clade â and of the most severely affected populations â in Africa (South Africa) and Asia (India and Taiwan) â within the global epidemic. This work helps to better define the viral mutation landscape that is essential both for future vaccines designed to corner the virus, and for successful HIV cure strategies.
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The Limits of Fire Support: American Finances and Firepower Restraint during the Vietnam WarHawkins, John Michael 16 December 2013 (has links)
Excessive unobserved firepower expenditures by Allied forces during the Vietnam War defied the traditional counterinsurgency principle that population protection should be valued more than destruction of the enemy. Many historians have pointed to this discontinuity in their arguments, but none have examined the available firepower records in detail. This study compiles and analyzes available, artillery-related U.S. and Allied archival records to test historical assertions about the balance between conventional and counterinsurgent military strategy as it changed over time.
It finds that, between 1965 and 1970, the commanders of the U.S. Military Assistance Command, Vietnam (MACV), Generals William Westmoreland and Creighton Abrams, shared significant continuity of strategic and tactical thought. Both commanders tolerated U.S. Army, Marine Corps, and Allied unobserved firepower at levels inappropriate for counterinsurgency and both reduced Army harassment and interdiction fire (H&I) as a response to increasing budgetary pressure. Before 1968, the Army expended nearly 40 percent of artillery ammunition as H&I – a form of unobserved fire that sought merely to hinder enemy movement and to lower enemy morale, rather than to inflict any appreciable enemy casualties. To save money, Westmoreland reduced H&I, or “interdiction” after a semantic name change in February 1968, to just over 29 percent of ammunition expended in July 1968, the first full month of Abrams’ command. Abrams likewise pursued dollar savings with his “Five-by-Five Plan” of August 1968 that reduced Army artillery interdiction expenditures to nearly ten percent of ammunition by January 1969. Yet Abrams allowed Army interdiction to stabilize near this level until early 1970, when recurring financial pressure prompted him to virtually eliminate the practice. Meanwhile, Marines fired H&I at historically high rates into the final months of 1970 and Australian “Harassing Fire” surpassed Army and Marine Corps totals during the same period. South Vietnamese artillery also fired high rates of H&I, but Filipino and Thai artillery eschewed H&I in quiet areas of operation and Republic of Korea [ROK] forces abandoned H&I in late 1968 as a direct response to MACV’s budgetary pressure. Financial pressure, rather than strategic change, drove MACV’s unobserved firepower reductions during the Vietnam War.
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