(a)
Radiotherapy & Chemotherapy
Radiotherapy:
Radiation therapy (or radiotherapy) is the medical use of ionizing radiation as part of cancer
treatment to control malignant cells. Radiotherapy may be used for curative or adjuvant cancer
treatment. It is often used as a palliative treatment, where cure is not possible and the aim is for
local disease control or symptomatic relief.
Chemotherapy:
Chemotherapy is the use of chemical substances to treat disease. In its modern-day use, it
refers almost exclusively to cytostatic drugs used to treat cancer.
In its non-oncological use, the term may also refer to antibiotics (antibacterial chemotherapy).
(b) Penumbra & Umbra
Penumbra:
The penumbra (Latin for mid-shadow) is the portion of a shadow that results from the source of
illumination being only partially blocked. Penumbras only occur when the source of light is not
a point-source. As the sun is a visible disc, solar shadows have penumbras. The penumbra part of
a shadow is contrasted with the umbra part of the shadow in which the light source is
completely blocked.
Umbra:
The umbra (Latin for shadow) is the darkest part of a shadow. From within the umbra, the
source of light is completely blocked by the object causing the shadow. This contrasts with the
penumbra where the light source is only partially blocked and there is only a partial shadow. The
umbra is also the comparatively dark central region of a sunspot.
(c) Springtides & Neaptides
Neap Tides
When the moon is at first quarter or last quarter, it’s located at right angles to the sun. Then the gravity of the sun and moon pull at cross-purposes, and the range between high and low tides is at its least. These are neap tides, and at such times the difference between high and low tides might be only inches a day.
Spring tides
But whenever there’s a full moon or a new moon, the Earth, sun and moon make a straight line - more or less - in space. Then the sun and moon’s gravity combine to create extremely high and low tides, known as spring tides.
(d) Vertebrates &. Invertebrates
Vertebrates:
Living Beings which do have spinal columns or backbone are said to be vertebrates. The internal skeleton which defines vertebrates consists of cartilage or bone, or in some cases both. The skeleton provides support to the organism during the period of growth. For this reason vertebrates can achieve larger sizes than invertebrates.
Invertebrate:
Invertebrate is a term to describe any animal without a spinal column. It therefore includes all animals except vertebrates.
(e) Fluorescent light & Neon signs
Florescent Light:
The common fluorescent tube relies on fluorescence. Inside the glass tube is a partial vacuum and a small amount of mercury. An electric discharge in the tube causes the mercury atoms to emit light. The emitted light is in the ultraviolet range and is invisible, and also harmful to living organisms, so the tube is lined with a coating of a fluorescent material, called the phosphor, which absorbs the UV and re-emits visible light.
Neon Signs:
Neon signs are produced by the craft of bending glass tubing into shapes. A worker skilled in this craft is known as a glass bender, neon or tube bender.
The neon sign is an evolution of the earlier Geissler tube (also called a Crookes tube), which is a glass tube for demonstrating the principles of electrical discharge.